all

Question 1

what are the 6 kingdoms and give a feature of each

Answer 1

1. monera (prokaryotes)
2. protista (eukaryotic, single celled)
3. fungi (heterotrophic, walls of chitin)
4. plantae (photosynthetic, autotrophic)
5. animalia (heterotrophic)
6. archaebacteria (anaerobic)

Question 2

how many phyla of animals are there believed to be?

Answer 2

40

Question 3

what is the order of the geographical periods starting from quaternary?

Answer 3

quaternary, tertiary, cretaceous, jurassic, triassic, permian, carboniferous, devonian, silurian, ordovician, cambrian, ediacaran, precambrian

Question 4

when (period) were the earliest animal and prokaryote fossils?

Answer 4

precambrian

animal- 1700mya

Question 5

when was there glaciation in the southern hemisphere?

Answer 5

carboniferous

Question 6

what environmental events occured in the Quaternary?

Answer 6

cooler glacial conditions, south polar ice cap forms, human evolution in last 5-3 my

Question 7

what is the burgess shale

Answer 7

soft bodied fossil bearing deposit (fossils from cambrian explosion) discovered by Walcott in 1909
- mostly benthic forms

Question 8

what 2 physical factors are important in animal evolution?

Answer 8

climate change and continental drift

Question 9

describe glaciation

Answer 9

climate change causes glaciation and it leads to isolation and separation of pops as they differentiate genetically. ice disappears and distinct species and populations appear.
hybrid zones where previously isolated species meet

Question 10

describe continental drift

Answer 10

Alfred Wegener proposed the idea in 1915. land masses once joined into supercontinent pangea but masses separated by continental drift due to plate tectonics. earths crust is comprised of 7 large plates floating on the mantle

Question 11

a) what 4 problems must animals solve to survive?

b) what must the body design be correlated with to meet these?

Answer 11

a)
1. getting food and O2
2. maintain salt and water balance
3. remove waste
4. reproduction
b)
1. environment
2. size of animal
3. mode of existence
4. genome constraints

Question 12

what % earths surface marine and roughly what % vertebrates are fish?

Answer 12

71%

50%

Question 13

which 2 zones are within the neritic zone- give depths and features

Answer 13

1. eulittoral (between rise and fall of tide- animals adapted to exposure like barnacles)
2. continental shelf/sublittoral (150-200m, sunlight benefits algae, coral reef is symbiotic relationship between poly and algae

Question 14

what 8 zones are within the oceanic zone and give depths?

Answer 14

1. continental slope (shore-3000+m)
2. epipelagic (200m)
3. mesopelagic (300-1000m)
4. bathypelagic (1000-2000m)
5. abyssopelagic (2000-3000m)
6. hadalpelagic (3000+m)
7. abyssal plain (3000-5000m)
8. mariana trench (11,000m)

Question 15

whats the difference between photic and aphotic zones?

Answer 15

light can penetrate photic zones and it is anywhere up to 200m deep. aphotic zone has increased pressure, decreased light and temp, more scarce food source, different feeding mechanisms

Question 16

give an example of an animal that can survive in the eulittoral or sublittoral zone

Answer 16

epaulette shark- when tide out lives in eulittoral zone, when low O2 can shut down its body but keep the flow to the brain and can use its fins to move in the pools

Question 17

give 2 examples of deep sea animals

Answer 17

anglerfish- light produced by bacteria help it survive by drawing in prey.

harp sponge- usually filter feeders but are carnivorous in deep sea

Question 18

define

a) pelagic
b) benthic
c) errant
d) sessile
e) sedentary

Answer 18

a) suspended or swimming
b) bottom
c) mobile
d) attached
e) unattached, immobile

Question 19

what is coastal upwelling?

Answer 19

as the sea moves there is water exchange between higher and lower waters and nutrients move from the bottom to the top

Question 20

give 11 advantages of the ocean

Answer 20

1. space- high productivity (28 x 10*9 c/yr)
2. biomass decreases from shoreline to open ocean
3. biomass decreases towards tropics (tropical waters have less temp change so less movement)
4. salinity 3.4-3.6%
5. oxygen
6. water movement constant
7. deep ocean currents- saltier water sinks moving slowly along bottom
8. iso-osmotic with body tissue fluids of many animals (osmoconformers, invertebrates will retain solutes to increase body conc)
9. buoyancy
10. fertilisation and development (external)
11. waste as ammonia

Question 21

give 4 brief features of a marine environment

Answer 21

• constant salinity, temp, O2
• provides support
• medium for fertilisation
• waste as ammonia

Question 22

give 6 brief features of a freshwater environment

Answer 22

• less constant temp, O2, velocity, volume
• osmotic regulation needed
• support
• eggs retained by parent
• direct development
• waste as ammonia

Question 23

give 4 brief features of a estuarine environment

Answer 23

• seasonal variations
• fresh and sea water mix
• support
• waste as ammonia

Question 24

give 6 brief features of a terrestrial environment

Answer 24

• daily and seasonal temp extremes
• O2 constant and uptake needs moist surface
• can suffer water loss
• no support
• internal fertilisation
• waste as urea/uric acid

Question 25

what generally happens to the lake condition in summer?

Answer 25

epilimnion (O2 rich) seperated from hypolimnion (O2 poor) by broad zone thermocline in summer due to rapid change in temp and O2 with increasing depth

Question 26

what happens as body size increases?

Answer 26

SA:V decreases and mechanisms other than diffusion are needed

Question 27

are free moving organisms often bilaterally or radially symmetrical?

Answer 27

bilaterally

Question 28

give an example of a constraint of the genome

Answer 28

there are limitations imposed by the ancestral design which are controlled by the animals genetic makeup- for example molluscs have the same basic body plan that is modified in different ways

Question 29

give 6 features of protozoans

Answer 29

- single celled - eukaryotic - motile - heterotrophic - have pellicle (cytoskeleton and cell membrane) - have test (hardened outer structure)

Question 30

describe locomotion of protozoans

Answer 30

- flagella to propel - cilia beating in metachronal waves - pseudopodia

Question 31

in what 3 ways is food acquired by protozoans? and what digests the contents?

Answer 31

1. pinocytosis (high conc food particles outside cell and low inside- pinched into vesicle) 2. receptor mediated endocytosis (receptors on cell membrane bind with molecules, engulfed into vesicle) 3. phagocytosis (large food particles bind to receptors and form vesicle) lysosomes digest contents

Question 32

how did the protozoans originate?

Answer 32

the endosymbiont theory- occured to utilise O2 as levels increased in atmosphere: 1. plasma membrane of ancestral prokaryote infolds 2. cell with nucleus and endomembrane systems engulfs aerobic heterotrophic prokaryotes by endocytosis 3. ancestral heterotrophic eukaryote formed with mitochondrion

Question 33

what are the 4 types of protozoan?

Answer 33

amoeboid apicomplexans flagellates ciliates

Question 34

what are the 2 types of pseudopodia?

Answer 34

lobopodia (more rounded) | filopodia (spikey)

Question 35

describe amoeboids

Answer 35

asexual, move by pseudopodia, free- living (amoeba) and parasitic (E.histolytica)

Question 36

describe the life cycle of amoeboid E.histolytica

Answer 36

- usually from faeces or uncooked food as a cyst that can survive 2-5 weeks in faeces - non pathogenic E.dispar form eats bacteria - virulent form invades mucus lining and causes an abscess to form - amoebe may reach bloodstream, liver, lungs, brain but is treatable

Question 37

describe apicomplexans

Answer 37

spore forming, sexual and asexual, spread by sporozoites, parasitic (plasmodium)

Question 38

describe lifecycle of apicomplexan plasmodium

Answer 38

species include: P.vivax, P.ovale, P.falciparum, P.malgrige 1. sporozoites divided at liver cells by fission forming merozoites 2. merozoites enter infect red blood cells (asexual division) 3. break out of RBCs, some develop into gametocytes 4. mosquito bites human picking up gametocytes in blood 5. gametes develop from gametocytes 6. fertilisation in mosquito gut forms diploid zygote 7. oocyst develops 8. sporozoites develop in oocyst, migrate to salivary glands 9. mosquito bites human, transferring sporozoites

Question 39

how can we attempt to control malaria?

Answer 39

drug treatment, GM males to attempt to sterilize them, gene editing for females so they don't produce eggs

Question 40

what is apicomplexan toxoplasma gondii?

Answer 40

cat is the definitive host where the parasite reproduces and the rodent is the intermediate host which transmits the parasite. parasite influences host making them less afraid of cats when infected so more likely to go near the cats to pass it on

Question 41

a) describe flagellates | b) describe its free living form

Answer 41

a) asexual (binary fission), move by flagella, free living (trichonympha) and parasitic (trypanosoma) b) trichonympha is in the gut of roaches and termites who eat cellulose which cant be digested. trichonympha breaks down cellulose into glucose producing enzyme B-glycosidase

Question 42

explain flagellate Trypanosoma brucei

Answer 42

- causes sleeping sickness - has variant surface glycoproteins so is hard for immunity to be developed - transmitted by tsetse fly - sub species Gambiense: fly human fly, if untreated death 2-3 years - sub species Rhodesiense: fly game fly, death 6-8 weeks, zoonosis can occur - thought tsetse fly attracted to plain surfaces emitting even light - can trap tsetse flies using the smell of cow urine

Question 43

describe ciliates

Answer 43

asexual (binary fission- macronucleus), sexual (conjugation- micronucleus), move with cilia, free living (paramecium)

Question 44

describe ciliate paramecium

Answer 44

- usually in ponds or freshwater - feed on micro-organisms - cilia waft food into oral groove and are used in locomotion - contractile vacuole controls water and expels excess liquid

Question 45

what are the 3 types of ova?

Answer 45

- isolecithal (little yolk, evenly distributed) - telolecithal (yolk concentrated towards vegetal pole) - centrolecithal (yolk concentrated at centre)

Question 46

describe the stages during the acrosomal reaction in sea urchins

Answer 46

- egg has protective jelly coat with chemoattractant properties causing sperm to migrate towards signals - sperm contacts the jelly coat and acrosomal vesicle with hydrolytic enzymes digests the jelly coat - acrosomal process forms and extends due to polymerisation of protein actin - process is coated with bindin which locks onto bindin receptors on vitelline layer - contact is made to egg pm stimulating sodium ion flow into egg, changing egg pm to positive - sperm cant cant on and are repelled (fast block to polyspermy) - sperm nucleus drawn into egg cytoplasm and fertilisation membrane forms and sperm and eggs merge

Question 47

what is the cortical reaction and slow block to polyspermy?

Answer 47

- ca released from cytoplasm causes cortical granules to be released and fuse with plasma membrane - enzymes and solutes digest adhesion between pm and vitelline layer - vitelline layer polymerised by some enzymes becoming hardened

Question 48

what does the potential of the egg pm changing lead to?

Answer 48

- metabolic changes in the egg - increase in protein synthesis and O2 consumption (prep for development) - ph change

Question 49

in sea urchin after how long a) sperm and egg merge b) replication and first division

Answer 49

a) 20 min | b) 90 min

Question 50

what are the 3 early stages of development?

Answer 50

cleavage, gastrulation, organogenesis

Question 51

what is cleavage and the 2 types?

Answer 51

- rapid division of a single cell into a ball of cells known as blastomeres - can be complete or incomplete - radial cleavage is where the mitotic spindles are parallel/perpendicular to vertical axis for second division, cells form on top of others, cleavage is indeterminate (fate not fixed early on), organisms have top/bottom oral/aboral - spiral cleavage is where the mitotic spindles diagonal to vertical axis of embryo, can cause twisting of embryo, mitotic spindles tilt, cleavage determinate, front/back anterior/posterior and top/bottom dorsal/ventral - continued cell division forms a morula which forms a blastula

Question 52

what are the 4 blastula types?

Answer 52

1. coeloblastula (hollow, 1 cell thick wall) 2. stereoblastula (ball of blastomeres) 3. discoblastula (blastomeres at animal pole) 4. periblastula (1 cell thick blastomere layer around yolky mass)

Question 53

what is gastrulation?

Answer 53

blastula forms a gastrula with 3 tissue layers formed - connectivity is lost at the bottom, blastopore forms which goes on to become mouth or anus - endoderm and ectoderm form with mesoderm in the middle

Question 54

what is the archenteron?

Answer 54

embryonic gut which the filopodia help to push up during gastrulation

Question 55

whats the difference between endoderm, ectoderm, mesoderm?

Answer 55

ecto: outer layer, epidermis, CNS endo: inner layer, gut, digestive tract, circulatory, respiratory meso: middle layer, body cavity coelom, bone, muscle, blood

Question 56

whats gastrulation in mammals like?

Answer 56

blastula forms trophoblast (placenta) or inner cell mass which forms epiblast (embryo) or hypoblast (extraembryonic membranes)

Question 57

describe the 3 main body cavities

Answer 57

acoelomate: flatworms, lacks body cavity between gut and outer body pseudocoelomate: roundworms, body cavity only partially lined by mesoderm coelomate: earthworms, body cavity lined completely with mesoderm

Question 58

what are the 2 cell types that can be formed after the 8 cell stage and describe them

Answer 58

protostomes - spiral and determinate cleavage - mesoderm formed by splitting of mesoderm (schizocoelous) - mouth develops from blastopore deuterostomes - radial and indeterminate cleavage - mesoderm formed from outpocketing of it (enterocoelous) - anus develops from blastopore

Question 59

how did porifera originate, what is the evidence and their likely ancestor?

Answer 59

from unicellular colonial flagellates around 700mya as flagellated cells are found in metazoans and many form colonies as well as molecular evidence links. choanoflagellates are the likely ancestor

Question 60

give 11 features of phylum porifera

Answer 60

1. parazoa branch 2. simple structure 3. successful and widespread 4. ancient group 5. rigid, sessile, perforated 6. lack muscle, NS and organs 7. usually hermaphrodite 8. asymmetrical 9. cellular level organisation 10. mainly marine 11. can form relationships with others to move such as on shells of hermit crabs

Question 61

how do porifera forms vary depending on where found?

Answer 61

flat and low growing where lots of wave action but are larger where less current movement in deeper water so are large to get as much food as possible

Question 62

briefly describe features of the structure of a sponge - ostium - osculum - amoebocyte - choanocyte - spongocoel - spicule

Answer 62

- water enters via incurrent pores (ostium) - cavity opens via osculum and water is expelled here - amoebocyte is where digestion occurs and food is taken from choanocyte and moved to other cells - choanocytes waft flagella to create a current and enable water flow into sponge, they line the inside of the sponge - spongocoel can help keep pores open - spicule can be calcareous, siliceous or made of spongin fibres

Question 63

how fast does water pass through a sponge?

Answer 63

at up to 20,000 times its volume in 24 hours

Question 64

what happens as the sponge gets larger?

Answer 64

the bigger the sponge the larger the choanocytes so a bigger current is generated

Question 65

give an example of a sponge

Answer 65

venus flower basket sponge- made of silicate and 75% tissues are syncitical (no cell boundaries between cells) and electrical impulses can travel through them

Question 66

how do sponges feed?

Answer 66

most are filter feeders taking in organic material from water or bacteria trapped in choanocytes which the amoebocytes engulf. but some are carnivorous with modified spicules to catch prey (harp sponge)

Question 67

why are filter feeder sponges important for coral reefs?

Answer 67

they generate nutrients. the ocean is poor in N and P. the C in the water is taken up by sponges and as bits of them die they are eaten by others so the other organisms then get the C

Question 68

can sponges regenerate?

Answer 68

in 1907 Wilson discovered that sponges can regenerate - put sponges through a sieve to see if reform and they did - also he mixed 2 different sponges before sieving and found they reformed as separate sponges and this was evidence for immunorecognition

Question 69

how do sponges reproduce asexually?

Answer 69

by budding or gemmules (internal buds that remain viable in harsh conditions and can form a new organism when conditions favourable)

Question 70

how do sponges reproduce sexually?

Answer 70

- usually hermaphrodite - sperm expelled by osculum and engulfed by choanocyte - moved around sponge until egg is reached - larvae retained until blastula stage

Question 71

how are sponges biochemical agents?

Answer 71

- some produce biotoxins - bright colours indicate toxicity - some chemicals have antibacterial activity

Question 72

what 2 branches does eumetazoa divide into?

Answer 72

radiata and bilateria

Question 73

give 8 features of cnidarians

Answer 73

- 2 body layers: epidermis/outer and gastrodermis/ inner - mesoglea between the 2 - limited organ development - simple form: blind sac with gastrovascular cavity - mouth=anus - simple nerve network and no brain - bundles of microtubules act as muscle - 2 forms exist: poly and medusa

Question 74

what do these cell types do in cnidaria? - cnidocil - epitheliomuscular cell - interstitial cell - neuron - enzymatic gland cell

Answer 74

- cnidocil: contains nematocysts, cover the tentacles - epitheliomuscular cell: muscle system - interstitial cell: can transform into other cells - neuron: forms nervous system - enzymatic gland cell: discharges enzymes into gut

Question 75

what occurs at the gastrodermis?

Answer 75

digestion occurs intracellularly after reaching the gastrovascular cavity

Question 76

what is a nematocyst?

Answer 76

- designed to capture and stun prey - contain coiled, hollow, barbed thread to ward off enemies or capture prey - stimulated mechanically and chemically - ca builds up, osmotic pressure changes - thread uncoils when stimulated and penetrates and paralyses prey - often inject venom/toxins

Question 77

whats key about the glaucus sea slug?

Answer 77

glaucus sea slug is a mollusc but it has nematocysts like cnidarians due to eating cnidarians and retaining the nematocysts as a form of defence

Question 78

what are the 4 main cnidarian classes?

Answer 78

- hydrozoa - scyphozoa - cubozoa - anthozoa

Question 79

give 3 features of hydrozoans

Answer 79

- usually colonial - sometimes show secondary polymorphism where polyp stage/parts can take on different functions - float

Question 80

whats the difference between the gastrozooid and gonozooid?

Answer 80

in cnidarians gastrozooid is for feeding and gonozooid is for reproduction

Question 81

what is hydra?

Answer 81

freshwater hydrozoan with no medusa stage and no planula larval stage

Question 82

what are siphonophores?

Answer 82

the most sophisticated hydrozoan- clusters of feeding polyp colony with individuals of different functions hanging below the swimming bell connected by a logn stem

Question 83

give 8 features of scyphozoans

Answer 83

1. medusa phase dominant 2. increase in sea temp can cause them to move to areas they aren't usually found with little nutrients and can disrupt food chains 3. radial symmetry 4. outer epidermis and inner gastrodermis separated by jelly like mesoglea 5. muscle cells allow umbrella to pulse for movement, as well as relying on currents 6. simple eye- pigment cup 7. statocyst senses gravity 8. rhopalium are nerve cells that can control rhythm of pulsations

Question 84

give 6 features of cubozoa

Answer 84

1. toxic (nematocysts can be venomous) 2. active swimmers (2m per second) 3. pursue prey such as fish 4. four evenly spaced tentacles 5. sophisticated eyes 6. can use navigation signals from shoreline and land to orientate and navigate themselves

Question 85

give 8 features of anthozoans (sea coral/anemone)

Answer 85

1. polypoid 2. colonial or solitary 3. medusa phase absent 4. water entering allows it to become rigid 5. water can circulate, entering via septal perforation- good for diffusion and respiration 6. septum increases SA 7. hollow tentacles 8. thick mesoglea

Question 86

how do anthozoans reproduce asexually?

Answer 86

- pedal laceration: slide along base dropping off bits of themselves - longitudinal fission: strip down the middle forming 2 individuals

Question 87

how do anthozoa reproduce sexually?

Answer 87

- hermaphrodite - fertilisation in gastrovascular cavity or the sea - planula larva produced

Question 88

describe the symbiotic relationship between clownfish and anemone

Answer 88

- clownfish lives in anemone tentacles but doesn't trigger nematocysts - fish benefits from feeding on what anemone has and gets protection - anemone benefits as fish helps increase O2 and nibble the tentacles to keep it clean

Question 89

describe the symbiotic relationship between anemones and stony coral

Answer 89

- carbon is fixed by zooxanthellae (photosynthetic algae in gastrodermis) - polyp generates waste, picked up by algae - food is caught by coral - zooxanthellae obtain inorganic ions from sea and aid in deposition of calcium carbonate reef skelton - if no zooxanthellae coral bleaching occurs

Question 90

within cnidarians what is the brief phylogeny?

Answer 90

anthozoa-> hydrozoa -> scyphozoa (medusa stage more derived as is only in the last 2 groups)

Question 91

give 9 features of platyhelminthes

Answer 91

1. bilaterally symmetrical 2. protostomes 3. no coelom (acoelomate) 4. triploblastic (3 body layers) 5. cephalisation 6. organs 7. dorso ventrally flattened 8. simple internal structure 9. no blood system, rely on diffusion 10. gut has one opening 11. simple excretory system involves the protonephridia (flagella waft fluid into it, absorbing useful substances)

Question 92

what is xenacoelomorpha?

Answer 92

basal bilateral simple structured organism that was thought to be platyhelminthes but aren't

Question 93

what are turbellarians?

Answer 93

free living platyhelminthes, non parasitic - covered in epidermis - nervous tissue concentrated at anterior end - the auricle detects chemicals - simple eye detects light - male and female reproductive tissue

Question 94

how was the regeneration of platyhelminthes studied?

Answer 94

- investigated if will reform when chopped up, they did - further down cut, longer head takes to form - small section cut then 2 heads can form - cells are pluripotent, being able to form any other cell in the body so regeneration can occur - studied further by Thompson and McConnell in 1950s/60s - trained flatworms ro be shocked when bright light displayed - cut up worms and reformed and both halves responded as though shocked - fed trained worms to untrained and they responded with shock response BUT observer bias proven

Question 95

what is penis fencing in platyhelminthes?

Answer 95

being female is costly so fight for which of the pair becomes the female. fight with penis to try to inseminate the other first

Question 96

give 6 parasitic adaptations of platyhelminthes

Answer 96

- loss of unwanted organs - penetration devices (enzymes produced so can burrow into host) - attachment devices (suckers/hooks) - protective devices (covering/ produce chemicals to stop digestive enzymes working) - transmission via vector - production of eggs in large numbers

Question 97

how many more eggs do parasitic flatworms produce than free living flatworms?

Answer 97

10,000-100,000 times more

Question 98

give 4 features of flukes- trematodes (platyhelminthes)

Answer 98

- found inside animals - have tegument (tough covering) that is non ciliated syncytium (no cell boundaries) - have oral and ventral suckers - mostly full of reproductive tissue

Question 99

describe the generalised life cycle of a fluke

Answer 99

1. egg hatched in water 2. intermediate host usually a snail- miracidium form here 3. germinal cells formed in sporocyst 4. redia formed 5. develops into cercaria with ventral and oral sucker 6. larvae released from snail to swim to second host- metacercaria formed

Question 100

what do blood flukes/ schistosomatidae do?

Answer 100

- cause schistosomiasis | - worms burrow into skin of human host and live in veins of intestine which can lead to blood in the urine

Question 101

what does D.spathaceum fluke do?

Answer 101

causes cataracts to from on eyes of intermediate host fish so are more likely to be predated by final host sea bird

Question 102

what does the lancet fluke do?

Answer 102

balls of mucus containing larvae are eaten by intermediate host ants causing them to clamp onto grass strands when colder weather making themselves more vulnerable to being eaten by final host cow/sheep

Question 103

how can trematodes be cooperative?

Answer 103

different forms of flukes can group cooperatively to carry out a function - soldier groups are aggressive, smaller and non reproductive - reproductive groups

Question 104

give 7 features of cestoda (platyhelminthes)

Answer 104

- live in gut - tegument - no gut themselves - scolex is the head region - strobila are the repeated segments - intermediate hosts - full of reproductive tissue

Question 105

what does the beef tapeworm (T.saginatus) do?

Answer 105

- enters muscle tissue of cow - bladder worms form in muscle tissue - human infected by ingesting meat if not cooked properly

Question 106

when does self fertilisation occur in tapeworms?

Answer 106

when only 1 tapeworm in host | mature as males first then females- sperm can be transferred to functional female area

Question 107

what are advantages of having a coelom?

Answer 107

- transport: movement of nutrients in fluid and gas exchange can occur) - gut moves independently of body wall - site for gametic maturation in fluid - hydrostatic skeleton (rigid but allows for movement)

Question 108

annelids can move by peristalsis describe this

Answer 108

- wave of muscle contraction - penetration anchor prevents back slipping when burrowing into sediment, the long thin circular muscles contract - terminal anchor allows for trailing part of body to be puleld forward, short fat longitudinal muscles contract

Question 109

a) what is the benefit of metameric segmentation in annelids? b) what is the prostomium and pygidium?

Answer 109

a) makes locomotion more efficient and precise | b) head and tail

Question 110

in annelids which structures run the length of the animal and which are repeated in each segment?

Answer 110

- gut and nervous system run length | - nephridium openings repeated

Question 111

in annelids what does the septum and nephridium do and what kind of circulatory system do they have?

Answer 111

septum divides segments, nephridium acts as a kidney and closed circulatory system

Question 112

in what 3 ways can segmentation be modified by?

Answer 112

1. restriction of structures to particular segments (reproductive tissue only in certain segments) 2. some segments develop special structures (head) 3. segments may fuse together

Question 113

describe ultrafiltration in annelids

Answer 113

1. ultrafiltration site is on a blood vessel forming primary urine 2. modification occurs to produce final urine which is released to the exterior 3. modification involves reabsorption of useful metabolites and secretion of toxins from blood or coelomic fluid 4. pressure of ultrafiltration due to muscular contractions of vessel wall

Question 114

what are the 3 main groups of annelids

Answer 114

- polychaeta - oligochaeta (clitellata- earthworms) - hirudinea (clitellata- leeches)

Question 115

give 3 features of polychaetes (annelids)

Answer 115

- parapodia and lots of bristle like setae - each segment has a pair of parapodia (gas exchange occurs here and it increases SA) - prostomium (head) well developed

Question 116

describe the 2 groups of polychaetes: errant and sedentary

Answer 116

``` errant - move a lot - well developed parapodia - active hunters - ragworm sedentary - tube dwelling - suspension feeding (water current passes between tentacles, tracts remove matter directing it to longitudinal food groove, large particles rejected and smaller ingested - sabella ```

Question 117

describe arenicola

Answer 117

- polychaete - sedentary - live in burrows/tubes - reduced parapodia as are burrowers - draws in sand to feed from one end of the burrow and deposit waste at the other end

Question 118

what is polychaete reproduction like?

Answer 118

dioecious, external fertilisation, spawning can be synchronous

Question 119

some polychaetes undergo epitoky, what occurs?

Answer 119

it is a body transformation such as metamorphosis into a reproductive form so can swim for longer, or will only spawn at a particular time of year

Question 120

give 4 general features of clitellata

Answer 120

- no parapodia - produce clitellum and cocoons (clitellum helps produce cocoon which is where eggs develop and are fertilised) - hermaphrodite - gonads are restricted to a few segments

Question 121

give 7 features of oligochaetes/earthworms

Answer 121

1. few setae 2. peristaltic locomotion 3. well developed septa used in peristalsis 4. some live on surface and some burrow 5. some feed on soil or bring food from surface into soil 6. gas exchange occurs on outer surface 7. reproduce by mutual sperm transfer

Question 122

describe reproduction in lumbricus worm

Answer 122

mutual sperm transfer - worms pair up head to tail bound by substance produced by clitellum - sperm released by male gonopore of 1 male travelling down sperm groove to opening of the other - clitellum produces lots of mucus and the cocoon - sperm is passed to female gonopore and eggs and new worms develo in cocoon

Question 123

give 10 features of hirudineans (annelid)

Answer 123

- no setae - restricted to 34 segments - mutual sperm transfer - no clear division of septa - predaceous - jaw like structures - eat small inverts - blood suckers (produce anticoagulant hirudin) - use symbiotic bacteria to break down blood and can take up to 10X body weight in blood - crawl with suckers as have no septa and the well developed longitudinal muscles aid the movement

Question 124

give features of a generalised mollusc

Answer 124

1. visceral mass surrounded by mantle covering which secrete shell if they have one 2. mantle cavity contains gills and cilia cause movement across the gill 3. nerve ring with branches goes to visceral mass and foot 4. foot can be used for movement (muscles act antagonistically acting on cells filled with fluid to develop waves of contraction) 5. radula is a feeding device of a conveyor belt of teeth that grind away at algae 6. open circulatory system 7. body plan very plastic 8. seven different types of mollusc

Question 125

describe the circulatory system of molluscs

Answer 125

open- in the haemocoel - oxygenated haemolymph pumped from ventricle to haemocoel bathing organs - drains into channels, chambers and branchial vessels - O2 picked up by conidia and transported to atria and ventricles an back to haemocoel

Question 126

what 4 changes make gastropoda different from the standard mollusc?

Answer 126

- development of head - dorso ventral elongation of body (often coiling of visceral mass) - shell forming a protective shield - torsion

Question 127

what is torsion and the advantage of it?

Answer 127

- protection of veliger larva stage - protection of adult - utilisation of oncoming water by gills

Question 128

what is a disadvantage of torsion and how has this been combatted?

Answer 128

anus over head | - modifications of mantle cavity to solve sanitation problem and water flow

Question 129

what is de-torsion?

Answer 129

undergone torsion but then gone back to normal as still have some twisting to do which occurs due to differential growth and muscular contraction- such as sea slugs

Question 130

what are the 2 types of spiralling in gastropods?

Answer 130

planospiral- symmetrical conispiral- asymmetrical initially thought to be planospiral but now conispiral as shifted over to the right side

Question 131

what are the most specialised gastropods?

Answer 131

pulmonates - no gill and mantle becomes vascularised into a lung wall - evolved when O2 short so needed another way to access it - can exploit terrestrial environment - hermaphrodite

Question 132

what is partula?

Answer 132

- gastropod that is species rich on the islands of tahiti - issue with predator african land snail - introduced predator rosy wolfsnail to eradicate african land snail but actually preferred partula snail

Question 133

what are lamellibranchs?

Answer 133

filter feeders

Question 134

give 8 features of bivalves

Answer 134

- most are lamellibranchs - most dioecious - laterally compressed - shell made up of 2 hinged parts - reduced head and nervous system - no radula - can use foot for feeding with cilia gathering food - draw in water into mantle cavity over gills

Question 135

give 3 examples of bivalves

Answer 135

a) mussels- attach themselves to rocks as are in intertidal zone due to byssus threads (strong silky fibres made from proteins to attach to rocks b) giant clams- have symbiotic relationships with algae for additional C source c) scallops- eyes on mantle cavity and can use shells for movement

Question 136

give 14 features of cephalopods

Answer 136

- marine carnivores - orientation of body changed - shell reduced/lost - closed circulatory system - foot modified into tentacles - mantle cavity relies in muscle contraction not cilia - can move by jet propulsion - some have ink sac which releases ink with irritant forming cloud so predator cant see - chromatophores in skin mean can change colour for disguise or mating - well developed nervous system (good memory and learning skills) - well developed eyes - not good at picking up sound - radula present so can produce neurotoxins - water pumped by muscular action

Question 137

describe the circulatory system of cephalopods

Answer 137

closed - have main heart and accessory hearts - blood pumped into gills - high metabolic rate and are active predators

Question 138

what are nautiloids?

Answer 138

molluscs - first appeared in cambrian - animals live in end of chambered shell which is filled with air rather than water to aid with buoyancy - can change amount of air and fluid in chambers - simple eye

Question 139

what does coleoidea include?

Answer 139

cuttlefish - internal shell/cuttlebone used as buoyancy device squid - shell reduced to proteinaceous pen for support octopus - shell vestigial/absent

Question 140

give 9 features of arthropods

Answer 140

- largest animal group - metamerically segmented - appendages on segments - grouped with nematodes as both undergo molts - marine, freshwater and air - no peristalsis but muscles are attached to cuticle - open circulation using haemocoel - special structures for gas exchange as body impermeable to gas - growth by ecdysis

Question 141

in arthropods how are they evolutionarily modified?

Answer 141

1. groups of segments specialised (tagmatization) | 2. specialisation of appendages

Question 142

what is a cephalothorax?

Answer 142

where the head and thorax join

Question 143

do arthropods have hox genes?

Answer 143

yes- first discovered in drosophila - controls anterior posterior axis - tells cells which segment they are in - highly conserved

Question 144

describe the cuticle in arthropods

Answer 144

- resilient to desiccation - allowed movement onto land - EPICUTICLE: made of proteins and wax- lightweight and waterproof - EXOCUTICLE: tough pigmented tanned layer where cross links form - MESOCUTICLE: protein and chitin bind to form glycoprotein - EPIDERMIS: secretes the cuticle

Question 145

in aquatic arthropods what can harden the cuticle?

Answer 145

ca salts

Question 146

describe ecdysis in arthropods

Answer 146

shed old cuticle and grow a new one - take up water/ air to make self bigger as cuticle hardens so new cuticle is bigger than body so can grow into it - after each molt new features form, increasing weight of organism

Question 147

what is the largest terrestrial and the largest aquatic arthropod?

Answer 147

terrestrial: coconut crab (50cm) aquatic: giant spider crab (4m)

Question 148

give 6 features of trilobites

Answer 148

- have 3 body regions (cephalon, thorax, pygidium) - went extinct 250-270mya - compound eyes made up of ommatidia- lens leading to pigment cells - scavengers and filter feeders - 2 branched limbs - most trilobites outlasted by sea scorpions

Question 149

when did sea scorpions go extinct and what are the 2 main regions?

Answer 149

extinct 250mya | prosoma and opisthosoma

Question 150

describe the main 2 tagmata of chelicerates

Answer 150

1. prosoma (cephalothorax) - 6 pairs appendages - chelicerae (pair of appendages at front of mouth, pincer like claws) 2. opisthosoma (abdomen) - no distinct head and no antennae

Question 151

describe the marine chelicerate of a horseshoe crab

Answer 151

- simple eyes used to detect opposite sex - gnathobase grinds up food - book gills used for respiration and are filled with blood and sea water and gas exchange occurs - chela of third walking leg gathers food - larvae develop in sediment - haemocyanin in blood - amoebocytes function like white blood cells

Question 152

what are terrestrial chelicerates known as?

Answer 152

arachnids

Question 153

give 6 features of scorpions

Answer 153

- mostly carnivorous (often use neurotoxins on prey) - earliest group of chelicerates - grab prey with chelicera - use pedipalps in mating (male grabs female, drops spermatophore and leads her over it) - females show parental care can live young can stay on her back for weeks - telson and aculeus are stinging apparatus to inject venom

Question 154

give features of spiders

Answer 154

- use pedipalps to mate - chelicera form fangs which release neurotoxins - small waist allows them to move their abdomen - spin silk (made of protein fibroin) produced by silk glands and released from spinnerets to form webs - can change consistency of silk - can use silk for ballooning where it gets caught in the wind so can move - can wrap food up and cocoon offspring

Question 155

in arachnids what do the malpighian tubules do and where does gas exchange occur?

Answer 155

malpighian tubes are used in excretion to absorb useful substances and expel waste gas exchange occurs at the book lungs and trachea deliver O2 to tissues

Question 156

why is B.kiplingi spider different ?

Answer 156

it eats plant material- the beltian bodies of acacia bushes

Question 157

what is the stabilimentum?

Answer 157

a structure on the web that could attract mates or prey or be to prevent birds flying into it

Question 158

can spiders act cooperatively?

Answer 158

T.nigroannulatum is a cooperative spider species where they work together to capture larger prey using their silk

Question 159

describe ticks and mites within chelicerates

Answer 159

ticks - ectoparasites - some can transmit disease such as lymes disease which affects the nervous system and can cause paralysis mites - free living and parasitic - dust mites and their faeces have strong allergens affecting people - varroa feeds on haemolymph of honey bee

Question 160

give 4 features of pycnogonida

Answer 160

sea spiders - abdomen very small - 4 pairs legs - reproductive structures carried outside body- males will carry the fertilised eggs - ovigers are used to clean the legs

Question 161

give 10 features of crustaceans

Answer 161

- predominantly marine but some occur in other in other environments - malacostraca main group - tagmatization and adaptive radiation of appendages - compound eye - pleopods can be used for swimming - 2 pairs antennae - 1-3 thoracic appendages may be incorporated into head (maxillipeds) - appendages biramous - filamentous branch can be enclosed to become a gill - legs have protopod and endopod as main 2 sections

Question 162

describe 5 features of the brine shrimp crustacean

Answer 162

- basic paddle like appendages moving in metachronal waves - legs can be used to capture food and respire - in salt lakes - modified pleopod forms chelae - abdominal region is used for swimming

Question 163

describe crustacean daphnia

Answer 163

- animal enclosed in a carapace which can open to allow water in - legs for food gathering and respiration - 2 pairs antennae, second pair well developed and used to swim - single compound eye - undergo parthenogenesis but in harsh conditions can reproduce sexually

Question 164

what is parthenogenesis?

Answer 164

reproduction from ovum without fertilisation

Question 165

describe crustacean barnacles

Answer 165

- heads can be cemented to shell - simple body, mainly thorax - no abdomen - hermaphrodite - largest penis to body ratio in animal kingdom - goose barnacle - parasitic barnacle sacculina which latches onto crab growing into it and can feminise males by attacking their adrenal glands

Question 166

what is the larvae of crustaceans?

Answer 166

nauplius larva

Question 167

within myriapods there are centipedes and millipedes, describe both

Answer 167

centipedes - head and trunk - dorso ventrally flattened with legs out of sides - well developed poison claw/maxilliped - predaceous millipedes - head and trunk region - spherical body with legs on it - move quickly - each segment has 2 pairs of legs - feed on plant material so no poison claw - emit hydrogen cyanide gas and other chemicals from repugnatorial glands - movement of air by muscles and diffusion - can lose water through spiracles - substances drawn into malpighian tubules from haemolymph

Question 168

what are the 3 tagmata in insects and what is found on the central one?

Answer 168

head, thorax, abdomen | thorax: 3 pairs legs and 2 pairs of wings

Question 169

what is the current hypothesis for the relationship among the 4 living subphyla of arthropoda?

Answer 169

chelicerata grouped with myriapoda and crustacea grouped with hexapoda

Question 170

give features of nematodes

Answer 170

- pseudocoelomate - cuticle of collagen and cross links between the proteins make it tough and flexible - 4 moults - lots of pressure in the body - epidermal layer secretes the cuticle - largest over 8m in sperm whale placenta - mostly dioecious - internal fertilisation - strong muscles at entrance and exit - nerve chords run down from body from simple brain - females larger and sex is environmentally determined

Question 171

describe c.elegans (nematode)

Answer 171

- free living - roughly 1mm - hermaphrodite - cells fate fixed early in development - set number of cells on body - first invertebrate genome sequenced

Question 172

describe the genes for enhanced longevity in nematodes

Answer 172

pha-4 is linked to enhanced longevity on restricted diet - if gene blocked no enhanced longevity - if overexpressed then longevity even longer

Question 173

describe parasitic nematodes and give 1 example

Answer 173

- parasitism evolved several times in nematodes - radiation accompanied evolution of flowering plants, insects, amniotic vertebrates - parasitic as juveniles, adults or both - one or more intermediate lost - root knot nematode infects plants so crop yield and economy decreases and the nematode drains nutrients and photosynthetic products of plants

Question 174

describe the parasitic behaviours of: a) s.morrisoni b) m.neotropicum

Answer 174

a) infects amphipod meaning they swim to surface of water in daylight, birds more likely to feed on them b) ant infected with nematode causes abdomen to swell and become red- attractive for birds to feed

Question 175

describe life cycle of a pinworm

Answer 175

indirect/ only in human cycle 1. eggs enter host by ingestion 2. eggs hatch in intestine 3. larvae mature 4. pinworm in human gut 5. impregnated female migrates to hosts anal region at night 6. zygotes released on host, bedclothes into airborne dust

Question 176

describe life cycle of hookworm

Answer 176

penetrates human skin and scrapes intestine 1. eggs develops in soil 2. rhabditiform larva hatches 3. larvae molts 4. penetrates human skin 5. larvae enter circulatory system 6. heart 7. lungs 8. trachea 9. larvae enter esophagus and is swallowed 10. larvae matures in intestine 11. hookworm adult in human intestine 12. fertilised eggs released in faeces

Question 177

what are asceroids?

Answer 177

- larger nematodes - up to 50cm - indirect life cycle - lots of them so can block gut

Question 178

what is the guinea worm (parasitic nematode) lifecycle?

Answer 178

1. live in subcutaneous tissue 2. form an ulcer 3. water touches it and larvae are released 4. larvae released into copepod which is the intermediate host 5. taken up in drinking water 6. penetrate gut and lodge into subcutaneous tissue

Question 179

what's an example of the filarial nematodes?

Answer 179

W.bancrofti - adults inhabit lymphatic glands - intermediate host - elephantiasis occurs (severe swelling of arms legs and genitals) 1. mosquito bites 2. adults in lymphatica 3. adults microfilariae migrate into lymph and blood channels 4. mosquito bites 5. microfilariae penetrate mosquitos midgut and thoracic muscles 6. migrate to head and mosquito's proboscis

Question 180

whats the benefit of symbiosis in nematodes?

Answer 180

most nematodes form symbiotic relationships with bacteria meaning works can be treated with antibiotics as they kill bothe the worm and the bacteria

Question 181

give 7 features of echinoderms

Answer 181

- pentamerous radial symmetry - body divided into 5 parts - not related to other radially symmetrical groups - 3 body layers - coelom - larvae bilaterally symmetrical - larvae show convergent evolution with other larvae even though not closely related to them

Question 182

whats the outer structure of echinoderms?

Answer 182

have an internal skeleton of ossicles - each ossicle caco3 has crystal structure separated by living tissue - ossicles can fuse to form a test (hinged hard outer casing) - some ossicles are minute/absent such as in sea cucumbers

Question 183

whats the purpose of tube feet/podia?

Answer 183

``` large= locomotion and feeding small= respiration and suspension feeding ```

Question 184

describe the water vascular system of echinoderms

Answer 184

helps operate the podia - tiedemanns can ingest waste material - contains canals full of fluid which go down each of the legs - water flows between ampulla and podium (suction cup at the end) - sea urchins have suction cup at the podium for grip - others have chemical reaction occur for grip

Question 185

what is mutable connective tissue?

Answer 185

- it can alter rigidity - under nervous control - due to changes in fluidity of collagen fibres in connective tissue - can eject organs to deter predators, these can be regenerated

Question 186

give 11 features of asteroidea

Answer 186

- pedicellariae: jaw like and remove waste that may accumulate - ambulacral ridge is where the podia are found - mouth on underside oral side - papula is for gas exchange and excretion - sophisticated nerve net - control comes from radial nerves connected to nerve junction - connection at nerve junction important to podia to travel in same direction - local control can occur so parts can temporarily function as brain - if cut some arms will continue in theri direction but others wont know which direction to follow - short arms may swallow food whole - long arms can grab prey such as prying apart mussels and eject stomach to digest externally

Question 187

give 10 features of ophiuroidea

Answer 187

brittle stars - photosensitive - no ambulacral groove or ampullae - podia not used in locomotion but are feeding - bursal sites: respiration - feed: scavenging, deposit feeding, suspension feeding - ossicles form plates over body - mucus on podia allow it to catch prey - can change colour due to chromatophores in skin - radial nerves with ganglia - legs and spines can grip substrate

Question 188

give 3 features of echinoidea

Answer 188

sea urchins - spines and podia used for movement - ossicles fuse to form test - aristotle's lantern made ossicles and forms a chewing device when feeding on rocks and larvae

Question 189

gives features of holothuroidea

Answer 189

- ossicles very small - bilaterally symmetrical pattern but podia in a radial pattern - crown of 10 dendritic tentacles (modified podia) - deposit and suspension feeders - podia used crawling/gripping - attached or irritated tubules from anus and toxin (holothurin) - anus leads to canals for respiration at respiratory tree

Question 190

give 8 features of crinoidea

Answer 190

sea lilies and feather stars - mouth on top - most ancient group - free living - can move by waving arms - ossicles present at calyx - ciliated ambulacral groove - sea lilies use arms to feed and are in the deep sea - feather stars are free living and use their arms to move and swim, suspension feeders

Question 191

give 3 features of hemichordates

Answer 191

- coelomates - half chordates - 2 main groups include enteropneusta and pterobranchs

Question 192

give 6 features of enteropneusta

Answer 192

acorn worms - burrow in mud forming tunnels - 9-200cm - proboscis collects food - gill slits are for respiration - larval stage echinoderm like - nerve net

Question 193

give 6 features of pterobranchs

Answer 193

sea angels - small (1-5mm) - sessile - colonial - lophophore (feeding device) - some have gill slits - can be traced back to graptolites in cambrian devonian period

Question 194

whats the resemblance of hemichordates to chordates?

Answer 194

- no notochord - no tail - nervous tissue can be hollow - collect food externally but do have gill slits

Question 195

whats the resemblance of hemichordates to echinoderms?

Answer 195

- similar larval stages - similar nervous systems - gill slits - more closely related to echinoderms than chordates

Question 196

what are the 4 features of a chordate?

Answer 196

1. notochord 2. dorsal hollow nerve cord 3. pharyngeal/gill slits 4. post anal tail

Question 197

give 7 features of invertebrates urochordates

Answer 197

- metamorphosis in adults means they lose many chordate features and only the gill slits remain for filter feeding - adults usually sessile - free swimming larval tadpole stage has all chordate characteristics - solitary or colonial - water in the buccal siphon and out the atrial siphon - larvae swim and settle their head adhering to the surface - notochord and tail loose turgor and are reduced

Question 198

give 3 examples of urochrodates

Answer 198

- sea squirt - salp (float in plankton) - larvacea (looks like larval stage but adult retains chordate features)

Question 199

give features of cephalochordates

Answer 199

- filter feed with gill slits - adults retain all chordate features - similarities with other deuterostomes - dorsoventral axis inversion in chordates - genes and proteins that would be expressed ventrally for chordates are expressed dorsally for non chordates

Question 200

what are deep sea hydrothermal vents and what is the community here like?

Answer 200

- form along mid ocean ridges (1500-3000m) - discovered late 1970s - extreme temp and pressure - ridges at boundaries of tectonic plates - cracks can form on sea floor and spreads as the plates move - cool water flows into cracks and is superheated by magma - hot vent fluid mixes with cold seawater - water forced out of plumes/black smoke full of nutrients and sulphides - vent fluid mineral rich to support ecosystems - primary producers chemoautotrophic microorganisms which break down sulphides oxidising them to form C compounds - bacteria can be consumed directly or form symbiotic relationships - vent communities have low numbers of species and diversity and high densities

Question 201

explain these deep sea vent organisms a) scaly foot snail b) yetti crab c) giant tube worm d) pompeii worm e) swarming shrimp

Answer 201

a) iron sulphides on foot and shell b) hair filamentous bacteria to protect from high temp c) - polychaete - 3m long - no gut - tissues have symbiotic bacteria - plume collects hydrogen sulphide and is transported in haemoglobin d) - gallery dweller in vent - tolerates high temp (80c) - deposit feeder - dorsal surface colonized by bacteria - hair is filamentous bacteria for heat protection - gill like structures increase SA - lots of haemoglobin to collect low levels of o2 e) - heterotrophs - bacteria grow in gill chamber (may farm them to feed on them) - dorsal organ eyes

Question 202

how many species are vent fauna and what % are vent communities only and what can provide a key part of the community?

Answer 202

>500 species 90% from vent only whale carcasses provide food and community for feeding on flesh (zombie worm digs into the bones and feeds on fat and protein)

Question 203

what are the 2 major groups of vertebrates and within the second what are its 2 major lineages?

Answer 203

- non amniotes (embryo enclosed and protected by mebranes and reproductive tract) - amniotes (additional set of membranes and include sauropsids/ birds and reptiles and synapsids/mammals

Question 204

how many orders are there in: a) mammals b) birds c) reptiles d) amphibians

Answer 204

a) 26 b) 23 c) 4 d) 3

Question 205

briefly explain how the terrestrial vertebrates came to evolve

Answer 205

550MYA: separate continents 300MYA: one single continent pangea through merging of others through continental drift- new niches form 150MYA: pangea broke apart vicariance/geographical separation allow diversity to occur

Question 206

how has the number of taxa within vertebrates increased over time?

Answer 206

increased exponentially with it reaching its max 12-14 mya and has been declining since

Question 207

what is the smallest fish and the smallest frog?

Answer 207

fish: paedocypris, 7.9mm. discovered 2005 in peat swamps frog: p.amauensis, 7mm, discovered 2012

Question 208

how do the reproductive behaviours of vertebrates vary?

Answer 208

oviparous (egg laying) viviparous (live young) ovoviviparous (live young from eggs that hatch within body)

Question 209

what type of speciation are darwin's finches?

Answer 209

allopatric

Question 210

what is convergence and evidence for it in vertebrates?

Answer 210

same selection for similarity - such as body shape in ichthyosaur, porpoise, shark - forelimb homologies in turtle, dolphin, horse, fruit, bat, chicken, human

Question 211

are reptiles monophyletic group?

Answer 211

no

Question 212

traditionally what were classification systems based on and what are they based on now?

Answer 212

all are based on similarity - traditionally phenetic methods where equal weight is given to all characters - now phylogenetic classification where characters are weighted based on evolutionary origin

Question 213

whats the difference between homology and analogy?

Answer 213

``` homology= shared ancestry between structures/genes in different taxa analogy= resemblance of function between organs with different evolutionary origins ```

Question 214

when studying vertebrate phylogeny based on DNA sequence data how many new species of fish, rodents, bats, primates are discovered each year?

Answer 214

>300 174 94 55

Question 215

roughly what % of vertebrates are endangered?

Answer 215

20%

Question 216

what have most vertebrates lost and what do they use their gill slits for?

Answer 216

lost notochord and gill slits used for breathing

Question 217

what is the endostyle for in vertebrates?

Answer 217

produces mucus and can retain iodine to make thyroxine

Question 218

what 10 main features make vertebrate chordates differ from the invertebrate ones?

Answer 218

- vertebrae - cranium - duplication of hox gene complex - development of neural crest - placodes - brain of vertebrates larger and with 3 parts - increased body size and increased activity - cant rely on ciliary action or diffusion - higher metabolic rate than invertebrate chordates - can sustain periods of anaerobic respiration

Question 219

describe the vertebrae

Answer 219

- usually replaces notochord - made of cartilage or bone - grows around nerve cord - support and protection - hagfish and lampreys don't have a fully formed notochord

Question 220

describe the cranium

Answer 220

- bony cartilaginous and fibrous | - protects the brain

Question 221

what are hox gene duplications associated with?

Answer 221

the evolution of other features and development of complex traits the first duplication was the origin of the vertebrates

Question 222

how did the neural crest develop and what is it responsible for?

Answer 222

1. neural crest plat gives rise to nervous system 2. neural tube forms as neural crest folds 3. as neural tube closes neural crest cells determinate and migrate out of the ectoderm 4. could be regarded as another germ layer- quadroblastic - responsible for new structures especially in the head - are precursors of neural crest in invertebrate chordates (tunicates and amphioxus have similar genes expressed to vertebrate neural crest formation)

Question 223

what are placodes?

Answer 223

embryonic structures giving rise to complex sense organs (hair follicles, feathers, teeth)

Question 224

give 10 primitive vertebrate features

Answer 224

- head extended beyond notochord - cranium supporting brain - tripartite brain with multicellular organs - can detect water movement - improved distance sensation - pharynx with specialized muscle - vascularised gut - 3 chambered heart - closed circulatory system with extensive capillary network - body fluid more dilute than water

Question 225

what kind of tissue do vertebrates have and describe this

Answer 225

mineralised tissue - contains unique mineral hydroxyapatite - means more resistant to lactic acid build up after anaerobic respiration - can be collagen fibres, proteinaceous tissue matrix or hydroxyapatite

Question 226

what are the 5 types of mineralised tissues and explain each

Answer 226

1. mineralised cartilage- forms main mineralised internal skeletal tissue of sharks 2. bone- internal skeleton of bony fish and tetrapods, highly vascularised and 70% mineralised, 2 types include dermal in skin and endochondral in body 3. enamel (96% mineralised) and dentine (90%)- associated with teeth or exoskeleton 4. enameloid- teeth and dermal scales of cartilaginous fish, 96% mineralised 5. cementum- fastens teeth into sockets, 45%

Question 227

what was the origin of mineralised tissues and why did they evolve?

Answer 227

- no mineralised tissue at start of vertebrate evolution - basic units in early vertebrates knows as dermal odontodes (dermal armour in skin of ostracoderms and are similar to shark denticles) - defensive structure - protected electroreceptors - regulation of phosphorus calcium and mineral storage

Question 228

give 2 examples of some of the earliest vertebrates

Answer 228

1. conodonts - 500MYA, unclear where in vertebrate evolution, have mineralized tooth like structures in pharynx 2. myllokunmingia- 530MYA, chordate features and skull and skeletal elements are made of cartilage

Question 229

where did early vertebrates originate from and what is the evidence for this?

Answer 229

marine environment 1. paleontological- earliest fossils in marine sediments 2. comparative physiology- invert chordates and other deuterostomes marine and body fluids are isotonic/same conc as mairn water

Question 230

what is an example of an extinct agnatha?

Answer 230

ostracoderms (500MYA) - jawless - derived forms thought to have paired fins - more derived than modern day agnathans - plates in mouth indicate most likely fed on soft bodied animals

Question 231

what are present day agnatha known as and what 2 does it include?

Answer 231

cyclostomes | lampreys and hagfish

Question 232

what is cyclostome haemoglobin like?

Answer 232

- alpha and beta globins - 500mya ancestral globin gene split giving rise to alpha and beta genes - jawless vertebrates the only vertebrates that don't show this alpha/beta split - common ancestor of lampreys and hagfish predates split so diverged before this

Question 233

give 11 features of lampreys

Answer 233

- most predaceous mainly attacking bony fish and marine mammals - sucker like feature to latch onto prey- oral hood with teeth to rasp at flesh - notochord supports body as vertebrae minute - tongue - single nostril on top of head - well developed eyes - pineal eye can detect light - respiratory tube combined with gut - velum prevents water flowing back into mouth - ventilates using gill slits by tidal ventilation drawing water in and out - larvae are filter feeders

Question 234

where do lamprey move to to breed and how?

Answer 234

adult life spent in sea but return to freshwater to breed (anadromous) - females use stones to build nests and lay eggs and sperm shed over the eggs find freshwater streams by pheromones released by larvae - pheromones made up of: petromyzonal sulphate, petromyzonamine disulphate, petromyzosterol disulphate - detected at low concentrations and produced in large quantities

Question 235

explain the lamprey colonisation of the great lakes USA in 1920s

Answer 235

- larvae are landlocked in the great lake so rather than returning to the marine environment they remain in freshwater - parasitic phase occurs in lake - mature adults migrate to streams - larval stage in streams then migrate to lakes

Question 236

what are the 3 main types of british lamprey?

Answer 236

brook lamprey- don't feed as adult (all over UK) river lamprey- coastal water as adult sea lamprey- larger and found in open ocean

Question 237

give 12 features of the hagfish

Answer 237

- scavengers and predaceous - slime produced could clog gills of other fish - can acquire nutrients through skin and gills - notochord for support - only vertebrates with blood isosmotic to sea - slime produced by glands - sex ratio female biased - single nostril for the intake of water - external gill opening - tongue with teeth - no larval stage (develop in egg) - can tie themselves in knots to feed or get rid of excess slime

Question 238

how did the jaw evolve?

Answer 238

- enabled vertebrates to feed on wider variety of prey | - evolved from anterior branchial arch/mandibular arch

Question 239

what arches support the gill slits and what does arch enlargement aid?

Answer 239

branchial | enlargement aids ventilation and arch is functioned in closing and opening entrance to pharynx

Question 240

what did Mallat propose?

Answer 240

1996- ventilation hypothesis - mandibular arch does not form functional gill arch in any living vertebrate or fossil form - first gill arch never used in respiration - lampreys and hagfish mandibular arch not used in respiration - gnathostome can suck in prey and grasp in with mandibular arch

Question 241

what do paired fins allow for and what is pitch and yaw?

Answer 241

to move around effectively and stabilize the body (also protection and mate attraction) pitch= up and down movement controlled by pelvic and pectoral fins yaw= side to side movement controlled by dorsal and ventral fins

Question 242

what are the genes responsible for the dorsal fin of lamprey also responsible for?

Answer 242

the midline and paired fins in bony fish and later on controlled limb development

Question 243

give 7 features of gnathostomes

Answer 243

- jaws containing teeth which form from mandibular gill (teeth homologous to denticles) - robust gill musculature - hypobranchial musculature allows for suction during inhalation and suction feeding - well developed vertebrae (centrum and ribs surrounding nerve chord) - mouth and gills operate as double pump - nostrils leading into 2 olfactory bulbs - lateral line system to detect mechanical pressure

Question 244

what are placoderms?

Answer 244

``` ancient gnathostomes (430-360mya) armoured prehistoric fish with head and thorax covered in armoured plates and the rest of the body is scales ```

Question 245

what does the clasper do?

Answer 245

used in reproduction as an intromittent organ for internal fertilisation to occur (placoderms)

Question 246

what are acanthodians?

Answer 246

spined extinct jawed fishes - some toothless others have tooth whorl - could be related to cartilaginous fish as share features with them - resemble sharks

Question 247

give 5 features of chondrichthyes

Answer 247

- first appeared 400MYA - cartilaginous skeleton make it manoeuvrable, can lighten the body - lipid filled liver can provide buoyancy - high blood urea concentration, less dense so more buoyant - most have hyostylic jaw suspension

Question 248

what is hyostylic and amphistylic jaw suspension?

Answer 248

hyostylic= upper jaw detached from skull but attached by gill arch so can move jaw independently of cranium amphistylic= ancestral form with some attachment to skull and support from gill arch

Question 249

what are the 2 main subgroups of chondrichthyes

Answer 249

- holocephali (rat fish) | - elasmobranchs (sharks, skates, rays)

Question 250

give 7 features of holocephali

Answer 250

- well developed pectoral fins - can have whip like tail - upper jaw fused to cranium (holostylic) - feed on crustaceans - spines can produce toxins - head clasper used in mating to grab females neck - head rich in mechano and electro receptors

Question 251

what are the 2 types of elasmobranchs

Answer 251

squalomorpha - no anal fin - live in cooler, deeper water - hammerhead shark (head shape could enable binocular vision) batoidea- skates and rays

Question 252

give 8 features of batoidea, elasmobranchs

Answer 252

- enlarged pectoral fins - benthic - some produce electric currents (rays can produce 200 volt shock) - rays have barb for defence - skates have dorsal fins on tails and lay eggs - rays give birth to live young - cephalic fins when swimming, such as manta ray, allow water in and filter feeding - skates can produce low current for communication

Question 253

what are elasmobranchs gut like?

Answer 253

short gut with spiral valve to increase SA

Question 254

what type of tail do elasmobranchs have?

Answer 254

heterocercal: asymmetrical with top longer than the bottom

Question 255

what are the scales of sharks ?

Answer 255

placoid scales - improves water flow over body - homologous to teeth - young sharks can use denticles to aid feeding

Question 256

what forms due to sharks lacking dermal bone?

Answer 256

teeth form within skin and a tooth whorl rests on the jaw

Question 257

what 3 types of receptors do chondrichthyes have?

Answer 257

mechanoreceptors- detect vibrations using neuromast organs chemoreceptors- acute sense of smell, 1 part in 10 bn, will turn to the side stimulated first electroreceptors- ampullary organs in the head of sharks and pectoral fins of skates and rays detect electrical impulses of prey

Question 258

what is. the vision and brain liek of chondrichthyes?

Answer 258

- well developed vision for low light intensities - rod rich retina with cells with crystals of guanine forming a mirror like structure behind the retina - brain proportionally heavier than other fish - similar brain to body mass ratio of some tetrapods

Question 259

what is the sequence of systems for chondrichthyes?

Answer 259

olfaction particularly if prey wounded or mechanoreception vision for prey detection- will bash into prey to smell blood if cant see use electroreception to attack kill prey by exsanguination (draining of blood) - bite force 1800kg, megalodon 18,000kg

Question 260

how do sharks reproduce?

Answer 260

- internal fertilisation - most species lay eggs and males fertilize them - males may wrap around female and insert his claspers into females cloaca - females skin may be thick to account for males latching on - can be oviparous - ovoviviparous - viviparous

Question 261

what are viviparous shark species like?

Answer 261

- some females secrete substances in reproductive tract - some ovulate to feed young - sometimes young feed on each other - some have yolk sac placenta - once born/ eggs laid there is no parental care

Question 262

compare general shark life history parameters to atlantic cod

Answer 262

- sharks take longer to reach maturity - larger size at maturity - slightly longer lifespan - fewer offspring in a 'litter' - reproduce biennially rather than annually - reproduce later in life

Question 263

give 6 features of osteichthyes and the 2 main groups

Answer 263

- >30,00 species - >95% all fish - bony fish - first fossil approx 400MYA - mineralised tissues as scales - radiated in devonian into the 2 groups actinopterygii (ray finned) sarcopterygii (lobe finned)

Question 264

describe 2 non-teleost osteichthyes

Answer 264

sturgeon - cartilaginous skeleton but though to have lost bone - swim bladder type structure - petrutable jaw - lost many scales, scoot instead - used in caviar industry paddlefish - cartilaginous skeleton and lost bone - extension from cranium full of organs detecting electrical signals - fish feeder species found in china and filter feeder in US - paddle detects electrical impulses, similar to ampullary organ of sharks

Question 265

give 12 features of teleost osteichthyes

Answer 265

- specialisation of feeding mechanisms - flexibility of bone of skull and jaw so can exploit a range of prey - jaws act as a suction device to increase the volume of the buccal cavity - feed by suction feeding (mouth opens, buccal cavity increases and expands to draw water in) - pharyngeal jaws - cichlids may account for diversity in diet and feeding - modified gill arches help process food in mouth - homocercal/symmetrical tail to provide powerful force and keep fish in 1 horizontal plane - swim bladder provide buoyancy - small scales - can use fins to attract females - lateral line system detecting water displacement

Question 266

what is different about the moray eel?

Answer 266

accessory second jaw that launches out to grasp and kill prey helping to move it down esophagus- raptorial pharyngeal jaw (lives in crevices so cant use suction feeding as well)

Question 267

how are swim bladders formed and what did ancestral bony fishes have?

Answer 267

ancestral bony fishes had lungs similar to lungfish - swim bladder formed by outpocketing of gut during development - initially developed as lung but is a swim bladder in bony fish - maintains buoyancy of fish - can compress if pressure increases in deeper water - can gulp at surface to increase volume of swim bladder with O2

Question 268

typically how do bony fish respire ?

Answer 268

mouth has pump which opens and closes drawing water in operculum covers gills water in mouth, over gills and out operculum continuous current created by mouth and operculum - blood and water in opposite directions (countercurrent exchanger so maximises amount of O2 going into blood) - warm blood from capillaries in muscle transfers heat to arterial blood

Question 269

what is an alternative way fish can ventilate?

Answer 269

ram ventilation - fish may swim with their mouths open rather than pumping mechanism - must be active for water to go over gills

Question 270

what is regional heterothermy in fish?

Answer 270

fast moving fish can keep muscles 10c higher than surrounding water- maintain different temp zones in different body regions

Question 271

what are anabantoid fish and the dwarf gourami?

Answer 271

obligate air breathers in order to survive | have lung like labyrinth organ where gas exchange occurs

Question 272

what does catadromous mean?

Answer 272

live in freshwater but migrate to spawn in marine environment

Question 273

give 6 features of eels (actinopterygii)

Answer 273

- european/north african and american - reduced fins and no pelvic fins due to living in vegetation and mud - undergo migrations when they spawn to marine environment (catadromous) - schmidt discovered eels spawn in sargasso sea in 1923 - suffering exploitation - swim by generating body waves that travel the length of the body

Question 274

what are 3 types of sarcopterygii?

Answer 274

lungfish coelacanth (deep sea fish thought to be extinct but rediscovered in 1938) tetrapodomorph fishes (gave rise to tetrapods)

Question 275

what are the 3 genera of lungfish?

Answer 275

neoceratodus- australia protopterus- african lepidosiren- s american

Question 276

give 4 features of lungfish?

Answer 276

- can use fins to move around on the floor as they burrow in mud and when water dries out - developed lungs allow them to breathe air in water with low O2 levels - lung is a modified swim bladder to absorb O2 and remove waste - as water levels fall lungfish burrow into bottom mud and form a cocoon of their own secretion of mucus and aestivale (enter torpor) through the dry season and can hibernate for up to 2 years

Question 277

what are the 2 main types of extinct amphibians?

Answer 277

1. osteolepiforms- up to 7m long, ambush predators. prehistoric lobe finned fish 2. elpistostegids- panderichthys, 385MYA, no dorsal or anal fins, prehistoric lobe finned fish, eyes on top of hea, reduced tail, extensive downward facing ribs, dorsoventrally flattened body and head with long broad snout, more closely resemble tetrapods

Question 278

in amphibians what was evidence for the beginnings of tetrapod middle ear?

Answer 278

a different spiracular region

Question 279

what is tiktaalik?

Answer 279

extinct 383MYA - midpoint between osteolepiforms and tetrapods - fish but have features resembling tetrapods - large ribs - flexible pectoral fins - longer snout to snap up prey - reduced gill covers and reduced water flow through gills

Question 280

are the evolution of tetrapods and terrestrial life linked?

Answer 280

they are 2 separate events

Question 281

give 3 examples of how tetrapod features are advantageous to animals in water

Answer 281

1. the frogfish- teleost that uses fish to move around substrate 2. eel catfish- teleost with flexible neck to gain food from terrestrial environment 3. mudskipper- uses fins to move on surface out of water and exploit terrestrial life

Question 282

what are 2 early tetrapod fossils?

Answer 282

1. acanthostega- 8 toes on front and hind limbs 2. ichthyostega- first tetrapods to leave water, 7 toes on hind feet, lateral line system, can breathe through skin, tibia fibula and first 2 rows of tarsal bones formed by preaxial radials, third row tarsal bones metatarsals and digits originate at postaxial branches

Question 283

what are fins homologous to?

Answer 283

limbs- they have the same genes for digit and rat formation but differential gene expression

Question 284

what is the reduction in digits in evolutionary lineages of birds and mammals associated with?

Answer 284

high speed running

Question 285

in what 2 ways can digits be lost ?

Answer 285

- reduced gene expression of ptch1 (cattle and pigs) | - digit forms but cell death then occurs (horses, jerboas, camels)

Question 286

what evidence is there for convergent evolution of embryonic limb skeleton in multiple mammal species?

Answer 286

species such as horses and jerboas both lost digits due to cell death but they are unrelated so it must be convergent evolution

Question 287

what are the 2 main ancestral tetrapod groups?

Answer 287

batrachomorphs and reptiliomorpha (gave rise to amniotes) which both gave rise to urodela and anura

Question 288

give 7 changes from land to water and the response to it allowing for the transition

Answer 288

1. increased solar radiation so need protection- chromatophores in skin absorb light rays 2. less support and less resistance to movement- strong skeleton and musculature and lateral undulations in tailed amphibians 3. light and sound waves travel differently in air so sense organs modified- fish like eye transformed in metamorphosis (lens flattened, eyelids and tear glands), evolution of eardrum 4. air has lower thermal stability so temp varies- ectotherms have low metabolism, may hibernate or spend prolonged time in torpor 5. O2 more abundant but gas exchange must have no water loss- skin vascularised, lungs primary site of gas exchange 6. water limited so needs to be conserved- keratin and mucus in skin, live in damp places, excrete urea and some uric acid 7. most return to water to breed, range of reproductive specialisation

Question 289

what are the 3 main groups of amphibians and when were the oldest fossils?

Answer 289

urodeles, anurans, caecilians | fossils: 290MYA permian showing urodele and anuran types

Question 290

give 10 features of urodeles

Answer 290

newts and salamanders - mostly 4 limbs - salamander body forms reflect differences in life histories and habitats - fish like undulations of trunk and tail to assist limb muscles in advancing and retracting limbs - 500 species - mostly internal fertilisation - spermatophores comprise a gelatinous base and sperm cap - variation in courtship display (can have elaborate secondary sexual characters - pheromone transfer by tail fanning in aquatic species or skin slapping, biting, rubbing in terrestrial species - mostly aquatic eggs and larvae (ovoviviparity in purely terrestrial species - paedomorphosis/neoteny (reproduction during larval stage)

Question 291

give 10 features of anurans

Answer 291

- most diverse and widespread group of amphibians - lost tail - rigid body with well developed legs - african clawed frog fish like with lateral line system - body form evolved because of advantage in swimming with hind legs - diversity in body shape and lifestyle - around 25 subfamilies - all carnivorous - body specialised for jumping (fused urostyle and tibia/fibula, specialised muscles in hind legs) - highly modified skeleton

Question 292

where is the generalised amphibian life cycle common?

Answer 292

temperate regions

Question 293

what is 1 factor that has led to range of life history adaptations?

Answer 293

evolutionary trend towards transferring as many stages as possible to the terrestrial environment

Question 294

describe the trends in reproductive diversity in amphibians

Answer 294

- predation pressures on land less than aquatic, requires convergent adaptation against desiccation - increasing egg and larval size enhances survival rate but trade off between producing fewer more costly eggs with longer developmental size or many eggs - often associated with many convergent modes of parental care

Question 295

what are foam nests?

Answer 295

produced by amphibians - secretions from oviduct - males and females produce them by movement of front/hind limbs - protects eggs from desiccation and predation - evolved independently and convergently within at least 6 phylogenetic lineages across all tropical continents

Question 296

where may amphibian eggs be laid?

Answer 296

on water overhanging leaves - tadpoles develop aquatically when fall into ponds - egg clutches sometimes folded into large leaves - can be accompanied with guarding of clutches by males - evolved independently in at least 3 groups

Question 297

describe different ways tadpoles may develop

Answer 297

- some have terrestrial tadpole development - ovoviviparity so eggs and tadpoles develop in the female oviduct - embryos of 3 species are nourished with secretions - mouth brooding and stomach brooding can occur (R.darwinii frog)

Question 298

explain parental care in the poison arrow frog

Answer 298

- males (2-3cm) have and defend territories of several hundred ,2 - terrestrial egg clutches and tadpoles hatch from eggs - tadpoles climb on parents back and are transported to aquatic sites - males or females can be responsible for parental care - small, ephemeral water bodies are usually predator free and contain no food - some species feed tadpoles unfertilised eggs

Question 299

for reproduction how do frogs mainly communicate?

Answer 299

- acoustic- sex pheromones play no/little role - nocturnal/crepuscular (active during twilight) so communicate acoustically - calls stereotypes with some species having different types of calls - calls can be produced by in or exhaling air on land or underwater - only males call - vocal sac amplifies calls, radiating call into circular directions

Question 300

what are the pros and cons of producing acoustic signals?

Answer 300

PRO: ease of signal variation, signals can go around obstacles, works in darkness, can adapt call rate and type depending on social contexts CON: signals travel short distances and cover short time periods, attract predators as well as mates, costly to produce, social interactions in chorus can increase costs

Question 301

explain the experiment carried out to capture the cost of singing in frogs

Answer 301

tungara frogs - played song of whine and whine and chuck - females choose males that make more chucks - more extra males in pond the more chucks played - predation risk increases with number of chuck playbacks - chorus size increases, predation risk decreases so overall advantage to complex songs

Question 302

as well as acoustic signals how else can amphibian species communicate?

Answer 302

through leg waving such as in stream living frogs

Question 303

what are some comparisons that can be made between triassic anurans and modern day anurans?

Answer 303

modern: more derived characters including shortening of body due to loss of vertebrae, elongated ilia, fusion of posterior vertebrae to form urostyle to support pelvic ilium, increased leg length to aid swimming and jumping

Question 304

what 2 bones in anurans are fusions and what do they act as?

Answer 304

tibio-fibula and radio-ulna | shock absorbers

Question 305

what is in the skin of anurans acting as a deterrent?

Answer 305

poison glands in skin

Question 306

give 11 features of caecilians

Answer 306

- burrowing or aquatic - legless and blind - appear segmented but just folds of skin - 180 species , purely tropical - subterranean terrestrial life requires specialised reproduction - internal fertilisation, sperm transferred by adapted cloaca - egg laying or viviparous - females can give birth to up to 9 offspring and have up to 60% body length adults - energy for growing first supplied by yolk then mother (uterine milk secretions from walls of oviducts) - foetal gill for gas exchange across oviduct walls, can be exchange of metabolic waste - specialised foetal dentitions for scraping oviduct walls

Question 307

what are 6 shared derived features of amphibians?

Answer 307

- smooth, moist, permeable skin - amphibian papilla in inner ear - operculum columella complex in ear - green rods in retina - pedicellate teeth (pedicle composed of dentine and separated by connective tissue) - levator bulbi muscle causes eyes to bulge forward

Question 308

what main line of diversification led to reptiles and birds ?

Answer 308

sauropsids

Question 309

what is an amniote and what are the 3 main extraembryonic membranes?

Answer 309

presence of amniotic egg chorion= surrounds everything allantois= nitrogenous waste deposited, vascularised and involved in gas exchange amnion= surrounds embryo

Question 310

what does the albumin and shell do in the amniotic egg?

Answer 310

albumin surrounds everything as source of water and proteins, provides protection shell surrounds egg and provides support

Question 311

what are 5 derived features of amniotes?

Answer 311

- skin permeability (thicker, keratinised, more lipids, waterproof) - scales, hair, feathers (thickening of epidermis) - costal rib ventilation creates pressure difference to draw air in - longer neck - more complex nerves controlling forelimb so increased movement and dexterity

Question 312

what's the difference between anapsid, synapsid, diapsid skulls?

Answer 312

anapsid- no arches synapsid- 1 hole, 1 arch diapsid- 2 holes, 2 arches

Question 313

did the ancestral sauropsida skull have holes?

Answer 313

no holes so diapsid condition must have developed convergently

Question 314

what type of skulls do these have? a) sauropsids b) turtles c) non mammals d) mammal e) sphenodon f) lizard g) snake h) dinosaur i) bird

Answer 314

a) ancestral anapsid b) modified anapsid c) ancestral synapsid d) derived mammalian synapsid with dermal bone surrounding braincase e) ancestral diapsid f) lower temporal bar lost g) upper and lower bars lost h) ancestral diapsid i) convergent with mammal condition

Question 315

whats the difference between non amniote and amniote skull?

Answer 315

non amniote- flat skull and single muscle mass originates from braincase and underside of dermal skull roof amniote- skull tall enough for jaw muscle to originate from top of head, muscles are attached through the holes and can bulge through allowing for more powerful jaws, have fenestra

Question 316

what are the 2 main groups of diapsids?

Answer 316

lepidosaurs- tuatara, snakes , lizards | archosaurs- crocodiles, dinosaurs, pterosaurs, birds

Question 317

when did archosaurs diverge from lepidosaurs?

Answer 317

permian

Question 318

give features of chelonia

Answer 318

turtles - fossils from 220MYA - most species withdraw neck into shell by bending it in vertical plane in s shaped loop - teeth lost over time - carapace has keratin on top and underneath is bone and is an extension of the ribs as they are fused to it - if muscles push gut downwards lung can contract - plastron has some bone in it but with keratin on the outside

Question 319

what migration behaviour does the herbivorous green turtle display?

Answer 319

migrates in carribean and south atlantic for feeding and reproduction breed on ascension island but feed off coast of brazil will return here year after year using olfactory cue to locate the sight (others use light, wave direction, magnetism)- development of hotels along coast confuse them

Question 320

what is the sex determination of turtles?

Answer 320

environmental sex determination and often temp dependent - females are produced at higher temps (but in lizards the males are produced at higher temp and usually the larger sex develops at the higher temp)

Question 321

what is the example of kemp's ridley turtles

Answer 321

increase in proportion females from 1985 onwards after incubation temperatures raised

Question 322

give 6 features of tuatara/ sphenodon

Answer 322

- spines on back - found in new zealand islands - diapsid skull - nocturnal and low body temp - mostly feed on invertebrates 2 complete arches of bone

Question 323

what are squamates?

Answer 323

reptiles, lepidosaurs- lizards and snakes

Question 324

give features of lizards and 2 examples

Answer 324

small ones often insectivorous larger ones often herbivorous dwarf gecko 1.6cm komodo dragon 3m (ambush predator with venom in saliva)

Question 325

explain limb reduction

Answer 325

evolved over 60 times and is associated with burrowing and living in vegetation surface dwellers with long tails and burrowers with shorter tails

Question 326

give 10 features of snakes

Answer 326

- specialised legless lizards - skull kinesis further increased by loss of upper temporal arch - branching from lizards in the cretaceous - very different eyes to lizards - change in gene expression leads to more thoracic vertebrae - reduction in limb development - lack pectoral and pelvic girdles - elongation reduces body diameter - flexible jaw - can wrap around prey stopping them from breathing by constricting blood flow to vital organs

Question 327

give 8 features of crocodilia

Answer 327

- teeth in sockets (thecodont) which is convergent to mammals - diapsid skull - secondary palate separating nasal from oral cavity - sensory structures around mouth sensitive to movement and touch so can help young with their mouth - used to be more diverse and extensive - snout used to manipulate food - parental care and communication - eggs buried underneath the soil

Question 328

what are the 3 main ancient fossils of crocodilia?

Answer 328

P.kapilimari D.andiniensis S.clarki

Question 329

what group did birds evolve within?

Answer 329

archosaurs

Question 330

what 3 possible phylogenetic origins have been considered for birds and which was proven to be correct?

Answer 330

1. direct descendents of crocodiles 2. descendents of unknown group within archosaurs 3. descendents of therapoda (small carnivorous dinosaur)- suggested by Huxley 1860 and was proven to be correct through phylogenetic analysis and fossil discoveries

Question 331

what is hugely conserved within theropod dinosaurs and what did theropod lineages undergo?

Answer 331

body size conserved- birds and relatives consistently small | lineages leading to birds underwent sustained miniaturization so body size decreased and specie evolved quicker

Question 332

around what time did the birds arise and what is the revised dinosaur evolutionary tree like?

Answer 332

early cretaceous | therapoda grouped with ornithischia (bird dinosaur) rather than as an outgroup)

Question 333

why is it hard to place bird dinosaurs on phylogenetic tree?

Answer 333

lot of branching that occured a long time ago and there are few fossils and limited data

Question 334

give 8 dinosaur features of birds

Answer 334

- egg laying - scales - s shaped neck - tridactyl foot - bipedal - toes bearing weight of body - wishbone - fused sternum

Question 335

how many digits did ancestral bird forms have and how many do modern day have?

Answer 335

used to have 5 digits but now only 3- first digit reduced and the second and third fused

Question 336

why may dinosaurs have had feathers?

Answer 336

for display and colouration and perhaps insulation

Question 337

give 12 features of archaeopteryx including reptile and avian features it possesses

Answer 337

- transitional form - paedomorphic skull - fossil with well developed feathers from mid-jurassic period 150MYA - first specimen found in germany 1860 - few links to other groups - 12 individuals found - size of crow - opposable first toe - asymmetrical feathers evolve for flight - reptile features include: thick bones, toothed jaw, no fusion of vertebrate - avian features include: well developed feathers, three fingers, s shaped neck

Question 338

what does the wishbone have and when must it have evolved before?

Answer 338

fused clavicles but must've evolved before birds as theropods also have it

Question 339

how does the pigeon compare to archaeopteryx?

Answer 339

pigeon brain larger and can process visual stimuli, pelvis more developed

Question 340

what 2 ancient birds were around in the early/mid cretaceous?

Answer 340

mononykus- from mongolia, strange forelimbs and no flight ability iberomesornis- spain, structural advances in forelimbs, ossified sternum and tail

Question 341

what 2 ancient birds were around in the mid/late cretaceous?

Answer 341

enantiornithes- most diverse group in cretaceous in almost all continents hesperornis- n america enaliornis- flightless sea birds, england

Question 342

in 1999 what did the national geographic announce?

Answer 342

discovery of missing link between birds and non bird dinosaurs archaeoraptor

Question 343

what is the most primitive known dromaeosaur?

Answer 343

microraptor

Question 344

when did modern birds diverge ?

Answer 344

about 150MYA

Question 345

within dinosaurs roughly how many times did flight evolve?

Answer 345

at least twice - birds and pterosaurs

Question 346

what is the ability of birds to fly linked to?

Answer 346

success as most diverse group of terrestrial vertebrates

Question 347

what are 5 pros to flight?

Answer 347

- efficient way of foraging - cost effective way of locomotion - very fast locomotion - colonisation of remote habitat - migrations across planet for hibernation and aestivation

Question 348

what are 3 adaptation to deal with constraints of flight?

Answer 348

- uniform in morphology compared to other classes of vertebrates - flying birds have limited size and weight range - muscle power needed to take off increases by factor of 2.25 for each doubling of biomass

Question 349

how many feather like forms do dinosaur fossils reveal ?

Answer 349

9

Question 350

what are the 2 theories for origins of avian flight?

Answer 350

1. small theropods would run along ground and leap into air to pursue prey or escape predators 2. arboreal theory- climb trees and glide down

Question 351

what is the WAIR theory?

Answer 351

wing assisted incline theory - could be earlier incarnation of arboreal hypothesis or combo of cursorial and arboreal - seen in some modern birds

Question 352

what is an alternative theory to the cursorial theory?

Answer 352

pouncing proavis hypothesis | - use wings to project and accelerate themselves at prey

Question 353

why until recently was it considered more likely flight evolved from cursorial stage where wings were used for prey capture?

Answer 353

- ambiguous morphological evidence of climbing abilities - lack of trees in locations where archaeopteryx found - spread of feathered forelimbs to wings was originally for stabilisation during running - archaeopteryx could most likely glide but ability for flapping flight due to lack of flexible wings

Question 354

when were archaeopteryx flying and what does this mean for dinosauran flight?

Answer 354

150MYA- so dinosaurus flight must've evolved even earlier

Question 355

what are 3 problems with the cursorial origin of flight?

Answer 355

- max running speed 2m/s but estimated min flying speed 6m/s so there's a velocity gap - high energy demands of evolving flight as it is a fight against gravity - problem explaining origin of flight stroke in earthbound organisms

Question 356

what 2 pieces of evidence are there in favour of arboreal evolution?

Answer 356

1. the hoatzin bird- lives in rainforest on leaves, evolved lysosome to digest cellulose, gut adapted to digest this, young hoatzin use claws to climb trees but they drop off when adult 2. feduccias claw arc analysis- concluded archaeopteryx was an arboreal climbing bird that glided from heights, compared archaeopteryx

Question 357

what is the recent discovery in 2001 and 2002 for dromaeosaurs?

Answer 357

new specimens were discovered in western china which show forelimbs similar to archaeopteryx and hindlimbs similar to ancient arboreal birds but were feathered.

Question 358

in the late jurassic where did flight evolve?

Answer 358

in paravian theropod dinosaurs

Question 359

what 5 ancient birds show evidence of modern feathers?

Answer 359

``` caudipteryx archaeopteryx confuciusornis enantiornithines euornithes ```

Question 360

where did feathers first evolve and why?

Answer 360

theropods not birds and for stability rather than flying

Question 361

what are feathers most likely homologous to and what functions other than flight are they for?

Answer 361

homologous of reptilian scales | also for thermoregulation, colouration, waterproof dressing

Question 362

what are the 4 main components of feathers? | and what is their structure?

Answer 362

b-keratin (>90%), lipids (>1%), water (8%), pigments | hooks interlock on barbs creating strong vanes

Question 363

what are the 6 types of feathers in extant birds?

Answer 363

tail, flight, semiplume, down, filoplume, bristle

Question 364

what are remiges and rectrices?

Answer 364

wing feathers | tail feathers

Question 365

give the 7 main principles of flight

Answer 365

- wings function as aerofoil/lift and propeller/forwards motion - shape, area, position can be modified - wings follow principle of cambered airfoil - bottom surface of wing pushes air forwards and down creating area of high pressure below the wing and low pressure above providing lift - increasing angle of attack increases lift by up to 15 degrees - small group of feathers called alula produce a slot in front of the airfoil to reduce turbulence - slots between feathers on wing tips reduce tip vortex

Question 366

what is cambered airfoil?

Answer 366

camber is the asymmetry of the wing with a convex dorsal side and concave ventral and increases maximum lift

Question 367

what are the 4 wing functional types and describe each as well as their aspect ratios and an example of each

Answer 367

1. dynamic soaring- high aspect ratio (length:width) to make use of vertical wind gradient- shearwater 2. elliptical- low aspect ratio, cambered, high maneuverability- pheasant 3. high aspect ratio- little camber, low wing loading- swallow 4. high lift wing- aspect ratio between 2 and 3, static soaring- rough legged hawk

Question 368

what movement are wing tips responsible for and what does this lead to?

Answer 368

thrust which leads to forward momentum at downward stroke through wings inclined from the horizontal plane

Question 369

in birds what is the pattern of air flow during inspiration and expiration?

Answer 369

unidirectional- higher O2 conc than mammals | air flows through peribronchial lung during both phases of respiratory cycle

Question 370

what are colours and patterns of wings important for? and what are colours a combinationof?

Answer 370

important for sexual selection and crypsis and are a combination of pigment and structural characteristics- reflect specific wavelengths depending on pigment particle size

Question 371

what are the 4. main pigments?

Answer 371

eumelanins: black/grey pheomelanin: red/brown carotenoids: red/yellow porphyrins: UV sensitive

Question 372

what is iridescence?

Answer 372

interferences of reflections from many layers of melanin platelets so the colour can change if viewed from different angles

Question 373

are feathers and flight older than birds?

Answer 373

most likely as is evidence for 4 limb flying

Question 374

which synapsids were the most common?

Answer 374

permian and carboniferous

Question 375

why did number of mammals increase?

Answer 375

increase in flowering plants and insects as a food source

Question 376

what did the ascendancy of dinosaurs almost do?

Answer 376

almost annihilated synapsid groups

Question 377

what are the 3 main groups that eventually led to mammals called and give features of each

Answer 377

1. pelycosaurs- basal amniotes with body and leg undulations used and undifferentiated teeth 2. therapsids- more derived, holes in skull larger, larger canines, limbs more underneath body, decreased size 3. cynodonts- changes in skull and skeleton, decreases size, more upright limbs

Question 378

describe mammal-like reptiles/non mammalian synapsids

Answer 378

- homodont teeth - other bones pushed back eventually becoming part of middle ear - zygomatic arch/cheekbone develops - jaw bone becomes prominent in lower jaw changing articulation of skull

Question 379

what's the difference between early amniotes and modern mammals in terms of limb orientation?

Answer 379

early amniotes have the same muscles for movement and breathing so hard to do at the same time BUT: mammals have limbs more underneath the body, lungs compress to push air out, when stretch out -ve pressure in lung draws air in, thorax and legs separate so can breathe and move at the same time

Question 380

what are 6 features of. early mammals and give 3 more general features of mammals

Answer 380

- small and insectivorous - egg laying - nocturnal and solitary - infant/mother bond strong - large olfactory bulbs - lots of rods in retina good for low light concentration endothermy, lactation and suckiling, hair for insulation

Question 381

describe the teeth sets of most mammals and how it could have evolved

Answer 381

diphyodont (2 sets) with precise occlusion to improve grinding surface- but is not possible to have precise occlusion in polyphyodont so diphyodont must have preceded precise occlusion - evolved as animals fed on milk early in life so didn't need permanent teeth until later

Question 382

whats the jaw structure and molars of most mammals like?

Answer 382

lower jaw narrower than upper so it can move from side to side - has premolars and more complex molar with upper and lower offset so occlusion can occur

Question 383

how did lactation evolve?

Answer 383

mammary glands are related to apocrine hair glands originally aggregating pheromones secreted milk may have been produced to protect eggs from desiccation and microbes evolved as nutritious secretion

Question 384

what is the evolutionary advantage of lactation?

Answer 384

- production of offspring is separated from seasonal food supply - mother not dependent on paternal care - makes viviparity less strenuous on mother

Question 385

describe suckiling

Answer 385

giving milk and is unique - there are tight seals in pharynx preventing fluids entering lungs and stomach in an uncontrolled way - seals separate breathing and swallowing

Question 386

what are facial muscles homologous to?

Answer 386

neck constrictor muscles of reptiles

Question 387

what are prototheria and give 2 features and 3 examples

Answer 387

monotremes - mammals that lay eggs/oviparous and feed their babies milk - monotreme refers to common rear opening (cloaca)used for reproduction and excretion - platypus and spiny anteater and echidna

Question 388

what are 3 monotremes and when did they diverge from each other?

Answer 388

duck billed platypus, short nosed and long nosed echidna | echidna and platypus diverged 19-48mya

Question 389

how many electrical receptors do platypus have in their bill?

Answer 389

40,000

Question 390

what are the 2 groups of theria?

Answer 390

metatheria (marsupials) and eutheria (placentals)

Question 391

in what 6 ways do metatherian mammals differ from eutherian?

Answer 391

- usually opposable digit on hind foot - more incisors and molars but fewer premolars - bifurcated reproductive tract, simple placenta in some species, pouch/marsupium present in 50% species - altricial young with 1% body mass - lower body temp and basal metabolic rate - smaller relative brain size

Question 392

where are modern day marsupials present?

Answer 392

S.America and Australia

Question 393

whats the difference between non-syndactylous and syndactylous?

Answer 393

non syndactylous have 4 independent digits but syndactylous have digits 2 and 3 fused together

Question 394

whats the difference between polyprotodont and diprotodont ?

Answer 394

poly: multiple incisors dipro: 2 lower incisors

Question 395

what families are included in order diprotodontia?

Answer 395

possums, koalas, cuscuses, kangaroos, wallabies, wombats, glider, rat kangaroo,

Question 396

what families are included in order dasyuromorphia?

Answer 396

antechinuses, quolls, dunnarts, tasmanian devil, numbat

Question 397

what families are included in order notoryctemorphia?

Answer 397

marsupial mole

Question 398

what families are included in order peramelemorphia?

Answer 398

bilbies, bandicoots

Question 399

what families are included in order microbiotheria?

Answer 399

monito del monte

Question 400

what families are included in order paucituberculata?

Answer 400

shrew opossums

Question 401

what families are included in order didelphimorphia?

Answer 401

opossums

Question 402

describe marsupial evolution

Answer 402

- Australia split from Antarctica 45MYA - S.America split from antarctica 30MYA - marsupials split from eutherian mammals around 100MYA - when land bridge opened between north and south america placentals moved from N to S and marsupials moved from S to N - australia isolated location with only marsupials

Question 403

what happened at the KT boundary?

Answer 403

possibly a meteorite strike so extinction occurred and approx 50% all genera became extinct including non avian dinosaurs caused a much colder climate and many groups wiped out

Question 404

when did marsupials and mammals diverge?

Answer 404

100mya

Question 405

when was the basal split among marsupial orders?

Answer 405

80mya

Question 406

what is the Wallace line?

Answer 406

geographical division in SE Asia | SE of the line is where marsupials occur and placentals north of it

Question 407

in terms of females what is marsupial reproduction?

Answer 407

- pouch/marsupium in 50% species - paired vaginal transport system - birth via pseudovaginal canal - 2 uteri - simple placenta - highly altricial young with short gestation - can have new born attached to nipple or fertilised blastocyst in uterus - similar oestrus cycle to eutherians, controlled by same hormones

Question 408

in terms of males what is marsupial reproduction?

Answer 408

- combined urogenital tract in males and females, cloaca - scrotum cranial to penis - bipartite penes

Question 409

what are the costs of being a placental?

Answer 409

- can't off load embryo, long gestation - female structure has to be altered for birth, birth canal and wider pelvis - placentals had to develop trophoblast to protect embryo

Question 410

what are costs of being marsupial?

Answer 410

- restriction of forelimb development | - reduced brain size, opportunity to learn by observation

Question 411

give an example of convergence in an arboreal mammal community?

Answer 411

lemurs and opossums - similar historical biogeography - similar habitats of rainforest - comparable diets - similar size - both have low fecundity with 1-2 young per year - similar general behaviour

Question 412

give an example of diet convergence

Answer 412

striped possum and aye aye possum both have an extended finger for extracting insect larvae from rotten wood

Question 413

give an example of gliding convergence

Answer 413

squirrel gliders (order diprotodontia) and flying squirrels (order rodentia)

Question 414

how many species does the IUCN list as being of concern in Australasia and why may the extinctions have occurred?

Answer 414

>200 species colonisation by aboriginal humans when europeans reached Australia and South America and when north American eutherians invaded

Question 415

in Australia what is the critical weight range for animals?

Answer 415

35g-5kg

Question 416

define ectothermy?

Answer 416

depending on external sources for body heat

Question 417

define poikilothermy?

Answer 417

organism whose internal temp varies considerably`

Question 418

define homeothermy?

Answer 418

any animal that retains entirely stable internal temp under normal conditions

Question 419

define endothermy?

Answer 419

generation of heat and regulation of body temp metabolically

Question 420

are all homeotherms ectotherms?

Answer 420

no- all ectotherms are homeotherms though

Question 421

animals need a source of heat which usually flows from the body to the environment, where do ectotherms and endotherms get this heat?

Answer 421

ecto- from sun and contact with rocks | endo- from chemical reactions of metabolism

Question 422

give 6 points about ectothermy

Answer 422

- heat body by basking - ancient but successful strategy - very high energy efficiency 50% - food energy available to increase biomass - very low energy requirements - ecological consequences: limit to where can live

Question 423

give 7 points about endothermy

Answer 423

- heat body using metabolism - derived state (evolved twice in birds and mammals) - low energy efficiency (1% energy available for biomass increase) - high energy requirements - temp independent of environment so wider range of habitats - need more food - can exploit more niches

Question 424

what does metabolic rate increase with and who is heat loss higher for?

Answer 424

increases with decreasing body size | higher for smaller animals due to an increasing sa/v ratio

Question 425

why may you not see small endotherms?

Answer 425

sa/v ratio so high that they cannot eat enough food to maintain body temp

Question 426

are ectotherms or endotherms generally smaller?

Answer 426

ectotherms

Question 427

do you see tubular or flat mammals/birds?

Answer 427

no as this shape would loose heat too quickly

Question 428

describe how desert tortoises can increase their biomass?

Answer 428

eat hardly anything and spent most of the day and year inactive but can increase biomass by 25% each year- by tolerating severe imbalances in energy, water, ion budgets

Question 429

describe the energy budgets of ectotherms and what they lack

Answer 429

- use burrows to thermoregulate - lack salt glands and kidneys so can't produce concentrated urine so can't excrete salt without losing lots of water - so retain salt and are osmotically stressed - means are tolerant different degrees of osmotic pressure

Question 430

what do desert animals rely on to escape the heat and cold?

Answer 430

temp differences between sunlight and shade and surface and underground burrows

Question 431

give 2 examples of how ectotherms show behavioural and physiological adaptations for temperature regulation

Answer 431

desert iguana- changes colour throughout day to alter absorption marine iguana- minimises surface area exposed to sun and creates a convective current

Question 432

what may tadpoles in the desert do when stuck in water bodies?

Answer 432

move around to cope with the different temperatures | cluster where cool water in midday and in the evening cluster in the middle where warm

Question 433

describe the efficiency of the garter scale activity in relation to body temp

Answer 433

as body temp increases the efficiency increases until a peak point but O2 consumption also increases

Question 434

in what 2 ways can ectotherms cope with very low temperatures?

Answer 434

1. freeze avoidance- contact with ice means risk of freezing so surface dwellers produce antifreeze and deep water fish can become supercooled 2. tolerate freezing- cells not completely frozen due to protection of cryoprotectant in cell in response to freezing, cells maintain low levels of aerobic activity, wood frogs can survive freezing in sub zero temps in arctic circle

Question 435

what is... a) thermoneutral zone b) evaporative cooling c) hyperthermia d) metabolic heat production e) hypothermia

Answer 435

a) between upper an lower critical temp b) above upper critical temp c) above upper lethal temp d) below lower critical temp e) below lower lethal temp

Question 436

what are endomesothermic sharks?

Answer 436

high body temp mean can swim faster and further can catch more prey - heat generating muscles heating up to 20c warmer than water temp - lamnidae sharks and tuna

Question 437

what is the migration of fish with endothermy like ?

Answer 437

larger maximum annual migration range that ectothermic fish

Question 438

what is opah?

Answer 438

lampris guttatus- first warm blooded endothermic fish

Question 439

is growth rate higher in endotherms or ectotherms?

Answer 439

endotherms

Question 440

wet fur is a poor insulator so what do aquatic mammals use to conserve heat?

Answer 440

blubber

Question 441

what is torpor?

Answer 441

adaptive hypothermia or temporary hibernation - body temp falls, metabolic rate reduced, slow respiration, reduced heart rate - smaller animals have more to gain from torpor as harder to keep body warm - larger bodies take longer and require more energy to warm up again

Question 442

describe endotherms in the desert

Answer 442

- heat gradient reversed: heat flows from environment to animal - harder than coping with extreme cold - use evaporation to cool but is risk of dehydration

Question 443

what's the difference between a dehydrated camel and one that has daily access to water?

Answer 443

dehydrated relaxes its control of body temp

Question 444

how many species of primates, where restricted to, what do most eat and when was the earliest known primate?

Answer 444

250 tropical regions omnivores some leaf eaters with cellulose fermentation 55MY old

Question 445

what are the 4 divisions of primates?

Answer 445

1. prosimians: basic primates- lemurs, bush babies 2. new world monkeys/ Ceboidea - marmosets, tamarins, spider monkey 3. old world monkeys (cercopithecoidea)- baboons, langurs 4. apes, hominids, humans (hominoid)- lesser apes, great apes, humans

Question 446

give 11 characteristics of primates

Answer 446

- retention of clavicle - shoulder joint allows for limb movement in all directions - elbow joint permits rotation of forearm - 5 digits on fore and hind limbs - usually one young per pregnancy - reduced snout - reduced number of teeth - claws modified into flattened nails - large barin - not all features in basal members - most features attributed to arboreal lifestyle

Question 447

whats the difference between strepsirhini and haplorhini?

Answer 447

strep- wet noses: tarsiers and prosimians | hap- dry noses: all other primates

Question 448

give 9 characteristics of strepsirhini

Answer 448

- usually small and nocturnal - long snouted - skull has an unfused frontal and symphysis and lack of postorbital closure - lemurs are native to Madagascar - long rostrum - postorbital bar - temporal fossa - no plate

Question 449

give 2 characteristics of haplorhini

Answer 449

- relatively short rostrum | - plate separating orbits from temporal fossa

Question 450

what does catarrhini comprise? and which od the two is more specialised and species rich? and how many premolars?

Answer 450

old world monkeys and apes - old work monkeys 2 premolars

Question 451

what are the 2 subdivisions/subfamilies of Catarrhini/old world monkeys

Answer 451

colobines | cercopithecines

Question 452

give 4 features and 2 examples of colobines

Answer 452

- in African and Asia - folivorous with complex fore stomach - arboreal with handles longer than forelimbs and long tails - stub thumbs - colobus - grey langur

Question 453

give 3 features and 3 examples of cercopithecines

Answer 453

- africa - omnivorous - increasingly terrestrial with short tails and limbs equal length - cercopithecine - Diana monkey - baboons

Question 454

give 3 general characteristics of new world monkeys/platyrrhini and what are the 3 subdivisions?

Answer 454

- 3 premolars - colonised S.America across Atlantic about 30 MYA by boat - no radiation into terrestrial or ape like forms - cebines, callitrichines, atelines

Question 455

give 2 examples of cebines

Answer 455

squirrel monkey and capuchin monkey

Question 456

give 2 examples and 2 characteristics of callitrichines

Answer 456

- marmosets - lion tamarin - secondary claws - produce twins

Question 457

give 2 characteristics and 1 example of atelines

Answer 457

- specialised climbers - prehensile tail - spider monkeys

Question 458

give 5 characteristics of hominoidea

Answer 458

- broad thorax and dorsal position of scapula assist balance in bipedal pose with centre of gravity near vertebrate column - caudal vertebrae reduced - frontal skull characterised by sinuses - 5 cusps on molars (OW monkeys have 4 so can tell them apart) - critically endangered

Question 459

give group size, no. of males in group, male behaviour and examples for each of these systems: a) female transfer b) male transfer c) monogamous d) solitary

Answer 459

a) small, one or many males, territorial and so empties kinship groups, chimp gorilla baboons colobus b) large, one or several, male hierarchy, most cercopithecines c) 1 family, one, both sexes for defence and parental care, gibbons and tamarins d) individual or female and offspring, no males, hushbabies orang-utans

Question 460

1. what has a dog like snout? 2. where do downward nostrils appear? 3. which groups have a tail and which species has prehensile? 4. which groups have callosities? 5. which have longer rear limbs than forelimbs?

Answer 460

1. lemur 2. OW moneys, lesser apes (Hylobatidae) and pongidae 3. lemurs, NW monkeys, OW monkeys, spider monkey prehensile 4. OW monkeys and lesser apes 5. lesser apes and pongidae

Question 461

whats included in pongidae and are males or females larger?

Answer 461

orang-utan, gorilla, chimpanzee, human | males larger

Question 462

what kind of vision did the ancestral vertebrate have?

Answer 462

tetra chromatic with 4 types of cone cells can see UV

Question 463

what are the 3 types of colour vision?

Answer 463

1. dichromacy (red/green colour blind) 2. routine trichromacy (OW and howlers) 3. allelic trichromacy (NW- individuals of same sex and species can differ and is frequency dependent advantage)

Question 464

what allows colour to be seen and what is colour vision?

Answer 464

cone cells in retina contain photopigments called opsin that see colour colour vision is the ability of an organism to distinguish objects based on wavelengths or frequencies of light they reflect emit to transmit

Question 465

in primates what are the signals not?

Answer 465

not pooled so genetic mutations can lead to new colour signals- lots of cone cells connected to single nerve fibre

Question 466

how many opsin do most mammals such as dogs have and how does this compare to humans and birds and fish?

Answer 466

2 humans- 3 birds and fish- more

Question 467

where is the short wave opsin coded for? and where are the medium and long wave opsin coded?

Answer 467

short- on chromosome 7 | medium and long- X chromosome

Question 468

give 4 features of dichromacy/colour blindness

Answer 468

- most NW monkeys - gene for small (s) opsin located on chromosome 7 - gene for L opsin on x chromosome - similar to red green colour blindness in humans

Question 469

explain the example of male squirrel monkeys with S and M opsin who were given gene therapy to introduce human L opsin

Answer 469

15-36% cells that were M opsins took up new opsin glen and expressed it, shifting preference to a longer wavelength in less than a year they could discriminate between red and green and blue and yellow

Question 470

give 3 features of routine trichromacy

Answer 470

- in all Catharrhini (OW monkeys, apes, humans) and howler monkeys - L opsin gene on x chromosome undergone duplication and the 2 copies evolved into M and L - all trichromatic as inherit autosomal S opsin as well as 2 different x genes

Question 471

describe the evolution of trichromacy ant he case of the howler monkeys

Answer 471

- genetic dating of opsin genes infer that gene duplication responsible for routine trichromacy occurred at separation of platyrrhine and catarrhine primates - howler monkey routine trichromacy evolved more recently - translocation may have occurred

Question 472

give features of polymorphic trichromacy

Answer 472

- some NW monkeys and some prosimians - only 1 copy but multiple alleles of L opsin gene on x chromosome - heterozygote females acquire different opsin from each copy of x chromosome - different x linked opsin alleles in heterozygous female expressed in different cone by random x chromosome inactivation - homozygote females and all males colour blind - thought to be 3 alleles for L gene in NW monkeys leading to 3 types of polymorphic trichromacy - 50-66% females usually trichromatic - may have persisted in NW monkeys due to benefits to a group of both trichromatic and dichromate

Question 473

what does it mean for a group having different alleles adapted to different wavelengths?

Answer 473

if in the same species can have both dichromatic and trichromatic females - dichromats: more frantic foraging, touch, sniff and bite more fruit - trichromats: make fear mistakes, forage more leisurely

Question 474

what can dichromats distinguish and how may this benefit?

Answer 474

distinguish patterns based on light that are invisible to trichromats- suggests better at spotting camouflaged predators or prey

Question 475

what must the maintenance of trichromacy be due to?

Answer 475

selective advantage

Question 476

describe fruit vs leaves in terms of dichromate and trichromacy

Answer 476

- ripe fruit often red but also reflects light in blue/yellow range which can be seen by dichromats - young leaves have red colouration so can be seen by trichromats but reflect similar blue/yellow signal to old leaves - in OW many fruits produced seasonally (must turn to young leaves when no fruit)

Question 477

what is the most folivorous monkey in NW?

Answer 477

enforcing need for routine trichromacy

Question 478

did coloration of monkeys evolve before or after trichromacy?

Answer 478

after as trichromatic have more skin showing than dichromates