Midterm Flashcards

Question

Adaptations to conserve energy during digestion

Answer 1

1. Parasitism – cestodes (tapeworms) a. Live in the human gut – small intestine; absorb the nutrients that are released 2. Mutualistic – microbiome a. Host of microbes in and on bodies i. Bacterial infection can change the diversity of microbiome; can cause health issues ii. Changes over time – infancy to adulthood iii. Changes based on – breastfed vs formula; vaginal vs c-section b. Gut bacteria – help break down macromolecules within DI tract c. Mutually beneficial – place for bacteria to live; helps organisms digest

Answer 2

Cellulose – glucose polymer; indigestible by most animals a. Dietary fibre – part of plant matter b. Microscopic organisms can digest – assist animals in digestion by living within digestive tract Solutions to digestion a. Symbiotic relationships with cellulose digesting bacteria b. Fermentation chambers in alimentary canals i. Cecum – pocket between small and large intestine; often where bacteria live in herbivores ii. Multiple stomachs – crops (pre stomach where mechanical digestion occurs); can live in one or all of the stomachs iii. Can have both – cows have multiple stomachs and fermentation in cecum c. Reprocessing food i. Coprophagy – animals that eat their own feces 1. Rodents and rabbits 2. Bacteria that are useful for cellulose digestion are in large intestine & cecum – they’re lost in feces 3. Eating feces will allow ingestion of cellulose digested by bacteria and reposition the bacteria in small intestine a. Most absorption occurs in small intestine, not large d. Organ expansion (comparing herbs and carns of the same size) i. Larger in herbivores than carnivores: 1. Cecum – for holding fermenting bacteria 2. Large intestine – for greater reabsorption of water and salts ii. Smaller in herbivores 1. Small intestine – used for absorbing proteins, fats, carbs (more necessary for carnivorous diet)

Answer 3

1. largest cause of waste removal 2. Enzymes remove nitrogen as ammonia in the breakdown of proteins and nucleic acids – very toxic to the body a. Order of toxicity: ammonia > urea > uric acid i. Converting to less toxic forms require increasing amounts of energy ii. Storing as more toxic forms requires more water to be present to dilute to safe levels 3. Different species convert to different compounds – can change based on environment and throughout lifetime (ex. tadpoles excrete as ammonia living aquatically; frogs store urea) a. Fish & aquatic animals – excrete as ammonia i. Free in water – can be continuously eliminated; don’t need to worry about it accumulating ii. Lots of water required to dilute to non toxic levels within the body iii. Requires very little energy to convert b. Mammals – typically convert to urea for storage i. Requires more water to be present and dilute ii. Requires more energy to covert than ammonia c. Birds, insects, land snails – convert to uric acid i. Requires the least water – least toxic ii. Largest energy requirements

Answer 4

filtering blood or ISF (if orgs don’t have blood) - Filtration – BP drives water and solutes from blood into filtrate - Reabsorption – reclaiming of useful solutes from filtrate back into blood; salts, sugar, hormones, water - Secretion – adding solutes to filtrate via active transport - Excretion – urine; filtrate is voided

Answer 5

1. Protonephridia – ex. flat worms a. Flame bulb – place of filtration; little cilia help draw in water (looks like a flame) b. Filtrate moves through tubules into external environment i. Small amounts of secretion and reabsorption will occur in tubules – not as much as other animals 1. Low solute concentrations – they are freshwater and can easily balance osmolarity 2. Metanephridia – ex. annelids (earthworms) a. Segmented – each segment will process the fluid from the previous segment i. Enters the collecting tubule through the internal opening in previous segment – ciliated funnel opening 1. Collecting tube is surrounded by capillaries – reabsorption and secretion ii. Coelom – large storage bladder tube; excretes out of external opening (each segment will have an opening) 3. Malpighian tubules – insects a. Tubules are emerged in hemolymph – removes nitrogenous waste and controls water and salt concentrations i. Filtered into midgut b. Filtrate travels to hindgut – reabsorption and secretion occurs i. Almost all water is reabsorbed – excrete is nearly dry; very good at conserving water ii. Secretion – bunch or collection of excretory organs 4. Kidneys & nephrons – vertebrates a. Humans have 2 kidneys - blood is supplied by renal arteries and output is veins i. Cortex - outer ii. Medulla - inner b. Nephrons – go back and forth between cortex and medulla i. Loop of henle’s deep into medulla - important for water conservation c. Glomerulus - ball of capillaries inside surrounded by bowman's capsule i. Filtration occurs here – blood pressure forces fluid into the tubules ii. Blood that leaves the glomerulus will merge into capillaries that surround proximal tubules (wrap around loop of henle) d. Proximal tubule – reabsorption occurs in proximal portion of loop of henle e. Distal tubule – secretion occurs in distal portion of loop of henle i. Merges into collecting duct – excretion occurs; exits kidney via ureter to bladder and out urethra

Answer 6

Patm = 740mmHg 1. Partial pressure of air = 160 mmHg a. 21% oxygen b. Only ~25% oxygen extraction from air – not very efficient; but there is 40x as much oxygen in air than water & air has a very low viscosity and is able to move through respiratory passages easily 2. Partial pressure of water < air a. Warmer and saltier water decreases o2 concentration b. Higher extraction rate of o2 that air – requires increased energy due to high viscosity of water i. Compensated for by the fact that most aquatic animals are heterotherms – use 1/10th of the energy homeotherms use to maintain body temp; energy can be used for oxygen extraction

Answer 7

Simple diffusion – limitations o Requires concentration gradients – move higher to lower o Moist surface area for gas exchange o Large surface area Moves slowly and over short distances o Maximum efficient distance = ~1mm (larger than this often requires bulk flow) o 10 years per 1 meter  Ex. blue whale is 30meters long – would require 400 years for gas to diffuse through a blue whale; they only live 80 years and would die before oxygen reached their tail All cells must be close to source of o2 or connected to the site of respiration o Cutaneous respiration – must be close to skin o Circulatory system – can connect the other cells to the source Respiratory surfaces – must be highly vascularized regardless of type to allow gases to enter the blood o Skin – cutaneous respiration o Specific organs – gills (aquatic), lungs (terrestrial)

Answer 8

1. Diffusion alone – small or thin animals; o2 and co2 moves along concentration gradients; all gas exchange occurs in respiratory surface and directly into tissues (no circulatory system) a. Porifera – have no true tissues b. Cnidaria – they can get very large but they are diploblastic but have no mesoderm i. Have mesoglea in between endo and ectoderm – doesn’t require o2 c. Platyhelminthes – flat; exchange occurs easily via cutaneous respiration d. Nematoda – cutaneous respiration 2. Diffusion and circulation – larger or thicker animals; all other phyla’s use

Answer 9

1. Cutaneous respiration – smaller animals a. Dependant on water – skin must remain moist; live in aquatic or damp environments b. Thin, highly vascularized skin – blood captures oxygen c. Large SA:V ratio – there must be more surface area of skin than volume of body i. SA = amount of skin & source of o2 ii. V = amount of tissues & demand for 02 (supply must be greater than demand 1. Below crossing point on graph – can use cutaneous respiration 2. Water breathing – gills for larger aquatic organisms a. Cannot use cutaneous respiration – small SA:V b. Evaginations of tissues – outward folding of skin i. Can be internal or external c. Non fish: i. External – relies on water currents; water flows over respiratory surface and exchange occurs 1. Aquatic worms and starfish ii. Internal – does not rely on water currents 1. Has structures to assist in water movement over gills a. Ciliated structures – gills and lophophore i. Encourage movement of water over respiratory surfaces b. Gill bailers – paddle like appendages that work to push water over gills (modified pereiopods/legs) i. Water flows back to front ii. Lobsters have d. Fish i. Ram jet ventilation – open mouth swimming 1. Inside of mouth has gill slits – flows out through slits on head ii. Buccal pump – moving cheeks; opening and closing mouth 1. Open mouth – water pressure in mouth decreases and causes water to flow in 2. Close mouth – water pressure in mouth increases and water flows out through the gills 3. Air breathing – lungs a. Invagination of tissues – infolding of tissues i. Always internal b. Mammalian lungs i. Series of branching tubes 1. Trachea – throat 2. Bronchi – larger branches 3. Bronchioles – smaller branches ii. Terminate at alveoli – site of gas exchange 1. Highly vascularized – gas is able to move into the blood iii. Large SA due to high folding – makes up for the small SA:V ratio since we only have a small site of respiration providing oxygen to large body 1. Still requires bulk flow and circulatory system 2. Approx. 100 m2 in humans iv. Ventilation 1. Inhalation a. Active muscle contraction i. Diagram – moves down ii. Intercostals – muscles between ribs; up and out b. Negative pressure – due to increased thoracic volume i. Atm pressure = 740 mmHg; thoracic = 700 mmHg ii. Allows passive movement of air into lungs – lungs expand 2. Exhalation a. Muscles relax i. Diagram – moves up ii. Intercostals – move in b. Positive pressure – due to decrease in thoracic volume i. Atm = 740 mmHg; thoracic = 780 mmHg ii. Allows passive movement of air out of lungs – lungs recoil c. Exhaled air is 18% o2 – 3% was taken into body (atm is 21%) c. Ventilation in birds i. Very efficient – air only flows in one direction & there is no mixing of stale and fresh air 1. Vs humans – inhale and exhale causes mixing 2. Multiple air sacs for gas exchange a. Air enters through mouth  posterior air sac (deoxygenated)  lungs (reoxgenated)  anterior air sac (deoxygenated) out mouth b. Lungs – parabronchi are tubules in lungs for gas exchange ii. Greater concentration gradient for gas diffusion 1. Partial pressure of oxygen in air is less at higher altitudes (flying) a. PO2 = >100 mmHg 2. Birds have a higher oxygen concentration within due to increased efficiency d. Insect tracheal system – don’t have full circulatory systems i. Trachea – tubes that open to the outside and allow exchange of air 1. Spiracle – respiratory openings on thorax and abdomen 2. Trachea branches within body – extend to nearly every cell in body; allows transportation of air without a circulatory system ii. Air sac – near large organs that require more oxygen; allow storage

Answer 10

1. None – use only diffusion a. Small or porous animals – all cells are near to the source of oxygen 2. Gastrovascular cavity – can be used for gas and nutrient transport or just nutrients a. Cnidarians – nutrient and gas exchange b. Platyhelminths (flatworms) – nutrients only; diffusion is sufficient for transport of gases since body is so flat 3. Closed or open circulatory systems – diffusion is not sufficient a. Components i. Pump – heart ii. Blood vessels transport – transports blood or hemolymph 1. Hemolymph – open circulatory system; mixed blood and ISF b. Absorption and secretion i. Gut – blood collects nutrients ii. Lungs/gills/skin – blood collects oxygen; co2 is released iii. Tissues – secretion of nutrients and oxygen; absorbs co2 and waste products c. Open circulatory system i. Components 1. Heart – pumps hemolymph 2. Open ended arteries – open directly into tissues 3. Sinuses instead of veins 4. Ostia – openings in the heart for returning hemolymph ii. Advantages – better for smaller animals with lower metabolism 1. Lower hydrostatic pressure – costs less energy to move hemolymph through the body (less resistance) iii. Insects – do not have a true circulatory system d. Closed circulatory system i. Components 1. Heart – pumps blood a. Blood – within blood vessels b. Lymph – bathing the tissues (ISF, ECF) 2. Arteries – brings blood to capillaries in tissues; high pressure vessels 3. Capillaries – at tissues a. Portal veins – conducts blood flow between 2 capillary beds i. Ex. hepatic portal vein – digestive tract to liver; liver filters blood before it’s transported to the rest of the body 4. Veins – low pressure vessels; bring blood back to heart ii. Advantages 1. Higher pressure – more effective at delivering nutrients and o2 within larger, higher metabolism animals

Answer 11

1. Fish – simplest a. 2 chamber heart – all deoxygenated blood i. 1 atrium – collects from body ii. 1 ventricle – sends to gills b. One circulatory loop c. Disadvantage – heart must rely on deoxygenated blood for metabolism (not optimal for functioning) 2. Amphibians a. 3 chamber heart i. 2 atria – one receives from body; one receives from pulmonary circuit ii. 1 ventricle – sends blood to pulmocutaneous circuit and systemic circuit b. 2 circulatory circuits i. Pulmocutaneous – o2 is received in lungs and through skin ii. Systemic circuit – body c. Advantages i. Heart receives oxygenated blood ii. Double circuit maintains blood pressure better – higher flow = higher nutrients and o2 delivery d. Disadvantages – o2 and no o2 blood mixes 3. Reptiles a. 3 chamber heart – partial septum i. 2 atria ii. 1 ventricle – partially separated b. Double circulation i. Pulmonary ii. Systemic c. Advantages i. Septum – reduces blood mixing in the heart 1. There is still some partial mixing (purple blood) 2. Right side – mostly deoxygenated 3. Left side – mostly oxygenated 4. Birds and mammals a. 4 chamber heart – complete septum i. 2 atria – receive blood ii. 2 ventricles – output of blood b. Double circulation i. Pulmonary circuit ii. Systemic circuit c. Advantages – no mixing of blood i. Right side – deoxygenated ii. Left side – oxygenated

Answer 12

1. Oxygen – bound to metalloproteins (have a metallic ion component that binds o2) a. Hemocyanin – one subunit; 2 Cu atoms i. Present in arthropods and many molluscs ii. Can only bind 1 o2 – copper is the binding component b. Hemoglobin – four subunits; 1 Fe each unit i. Each Fe can carry one o2 – max is 4 o2 per Hb ii. Exhibit cooperativity – when one releases, the others are more likely to release; same for binding c. Percent saturation of Hb i. At rest  ~30% is unloaded ii. Exercising  ~80% is unloaded 2. Carbon dioxide a. At the tissues i. High co2  diffuses from tissues to capillaries into RBC ii. Within RBC 1. Co2 + h2o = h2co2 = hco3- + H+ a. H2co3 = carbonic acid  splits b. Hco3- = bicarbonate  moves into plasma and is transported to lungs 2. Hb binds H+ and ~5% co2  transported to lungs 3. Carbonic anhydrase – adds water to reaction b. At the lungs i. Low co2  co2 diffuses from capillaries into alveoli 1. Movement causes reaction to shift to product more co2 and use up more hco3- ii. Within RBC 1. Hco3- + H+ - h2co3 = co2 + h2o 2. Hb releases co2 and H+ 3. Carbonic anhydrase – removes water from carbonic acid

Answer 13

Organisms are multicellular and 2n 1. Haploid stages a. Gametes (n) – formed via meiosis 2. Diploid stages a. Zygote (2n) – formed via fertilization b. Embryos (2n) i. Morula – solid ball of cells ii. Blastula – hollow ball of 1 layer of cells iii. Gastrulation – 2-3 layers of cells iv. Neurula 1. Neural tissue differentiation – only occurs in chordates 2. Organogenesis – differentiation of germ layers into organs c. Larvae – can feed themselves; may undergo metamorphosis d. Juvenile – look like adult but not sexually active e. Adult – able to produce functional gametes

Answer 14

1. Meiosis – gamete formation (in animals) a. Mitosis will occur during embryo formation 2. Steps a. Primordial germ stem cell – divides mitotically into spermatogonium/oogonium b. Spermatogonium/oogonium – 2n; mitosis into primary oocyte/spermatocyte c. Primary oocyte/spermatocyte – undergo meiosis I to form secondary i. Females – some organisms will have all primary oocytes present at birth; arrested in meiosis I d. Secondary oocyte/spermatocyte – formed upon completion of meiosis I i. Females – arrested in metaphase II; ovulated this way e. Spermatid/ootid – formed upon completion of meiosis II i. Females – only occurs after fertilization ii. Males – occurs prior to fertilization f. Gamete – differentiation creates sperm or egg (has polar bodies)

Answer 15

1. Sexual a. Requires 2 gametes – egg and sperm i. Slower b. Variation in offspring i. Usually 50/50 male to female ii. Works well if there are environmental changes – adaptations from genetic variation 2. Asexual a. Gametes optional – only the egg is required if they are required (parthenogenesis) b. No variation (except parthenogenesis) – only mitosis, no meiosis i. Will be genetically to parent if no errors occur – will all be female (except in parthenogenesis) ii. Works well in stable environment in which the parent is well adapted to – thrive with little to no environmental change iii. Very rapid c. Types i. No gametes 1. Budding – cnidarians 2. Gemmules – sponges a. Internal buds/mass of cells – spit out of organism 3. Fission – cnidarians, platyhelminths, echinoderms a. Splits into 2 organisms ii. Parthenogenesis – gametes (egg) required 1. Asexual reproduction that uses the female reproductive tract

Answer 16

1. Bees and wasps a. Queen (2n) – stores sperm in spermatheca for when she wants to fertilize i. Eggs (n) – produced via meiosis 1. If fertilized – forms zygote and develops into female 2. If not fertilized – “zygote like” haploid offspring; develops into male worker bee b. Male workers – produce sperm via mitosis (males are n and sperm are n) 2. Daphnia – freshwater org a. Female (2n) – produce eggs via mitosis (2n) i. Eggs develop into clones 1. Good for low predation and adequate food conditions – won’t need genetic variation to survive 3. Whiptail lizard – all are female a. DNA doubles in primordial germ cells (4n) i. Gametes (2n) are produced via meiosis – will have all necessary chromosomal content without fertilization b. Undergo mating behaviour to release egg i. Triggering ovulation in animals 1. Humans – hormonal 2. Lizards – hormonal and behavioural ii. Acting as female – increases estradiol & decrease progesterone; triggers ovulation iii. Acting as male – increases progesterone & decrease estradiol 4. Turkeys – produces non identical offspring from parthenogenesis a. Females can lay unfertilized eggs (asexual) – virgin chicks will develop into toms (males) i. Female chromosome is ZW & male is ZZ (opposite of human) 1. Female gametes will be WW or ZZ – haploid cells are converted to diploid a. WW – will die b. ZZ – will become males 2. Humans – YY couldn’t exist & females wouldn’t be able to produce males if they were hypothetically able to undergo parthenogenesis

Answer 17

1. Dioecious species a. 2 houses i. Male individuals – produce sperm ii. Female individuals – produce egg b. 50% of population are potential mates – 50/50 male and female 2. Monoecious species a. 1 house i. Hermaphrodites – have egg and sperm within one body 1. Simultaneous hermaphrodites – both sexes as the same time 2. Sequential hermaphrodites – starts as one and develops into another later in life a. Protandry – starts as male i. Ex. clown fish – starts as male; largest will develop into female to lay eggs 1. If largest female is killed – second largest will become female out of necessity b. Protogyny – starts as female b. 100% of population are potential mates – evolutionary advantage c. Types of fertilization i. Self fertilization – rare ii. Mutual cross fertilization – norm 1. Sperm of each organism will fertilize the egg of the other – double fertilization

Answer 18

1. Eggs – large non motile (unlike sperm) cells containing yolk 2. Forms from 1 of 4 daughter cells of meiosis – 3 polar bodies a. Differs from sperm – all 4 become sperm 3. Yolk – feeds offspring a. Fat and protein rich granules within the cytoplasm – nourishment for embryo b. Variable amount and distribution – due to time required to develop into larval stage (can then start acquiring nutrients from another source) i. Isolecithal – small amount of yolk evenly distributed throughout ii. Mesolecithal – moderate amount of yolk concentrated at vegetative poles iii. Teloecithal – lots of yolk evenly packed 1. Will be in vitro longer – requires more nutrients 4. Structure a. Protective jelly coat – exterior to vitelline layer b. Micropyle – narrow canal that lets sperm pass through the jelly coat (can’t move through jelly layer) i. Present in fish, insects, cephalopods ii. Not present in all animals c. Vitelline layer – separates yolk from jelly coat d. Perivitelline space – between vitelline and oocyte membrane e. Cortical granules – cells within yolk (within oocyte membrane)

Answer 19

1. Cells required in mammals a. Secondary oocyte b. Sperm 2. Acrosomal reaction – head of sperm has acrosome; fuses with jelly layer and causes release of enzymes which digest a whole to egg membrane 3. Molecular recognition a. Acrosomal process – extends from surface of sperm head and binds to receptors on oocyte membrane i. Molecular recognition ii. Ensures same species – important in external fertilization 4. Nuclear fusion a. Sperm fuses with oocyte membrane – triggers completion of meiosis II in 2° oocyte i. 2 nuclei result 1. Nuclear fusion – sperm nuclei fuses with one nucleus (2n) 2. Polar body – leaves egg and is absorbed by the body b. Cortical reaction – cortical granules fuse with plasma membrane; causes the sperm receptors to fall off i. Fertilization envelope forms ii. Prevent polyspermy

Answer 20

more than one sperm fertilizing egg (wrong number of chromosome) 1. Fast block (1-2 seconds) – due to membrane depolarization a. Influx of Na+ diffuse into egg – cause inside to become more pos and outside to become more neg so sperm can’t penetrate 2. Slow block (20-60 seconds) – fertilization envelope raises a. Due to cortical granule reaction – vitelline layer is lifted away and hardened to form fertilization envelope

Answer 21

1. External fertilization – gametes are released into environment and fertilization occurs outside of animals body; a. Need wet environment b. Requires synchronous release of gametes i. Pheromones – chemical signalling; causes other sex to also release gametes ii. Environmental cues – temp, day light (photoperiod), length of day 1. Fertilization blooms – lots of gametes released c. Tonicity – gametes require regulatory mechanisms to withstand tonicity of environment i. Ex. saltwater or freshwater 2. Internal fertilization – 2 types a. Direct deposition – common mechanism i. Copulatory organ – typically males deliver sperm; females have a receptacle or a storage area for sperm until female wants to use egg ii. Courting behaviours – leads to cooperative copulation b. Indirect deposition – male produces spermatophores; female picks it up (do copulatory act) i. Spermatophores – package of sperm that can be delivered to a females ovipore 1. Ovipore – opening on a female that is able to pick up package of sperm ii. Common in arthropods and salamanders

Answer 22

1. Oviparity – deposits egg outside body (ex. chicken) a. Pro – can produce more offspring because they don’t need to store them b. Con – risk of predation; mother can only lay eggs when theres lots of nutrients available (needs to be able to feed embryo) 2. Ovoviviparity – stores egg within oviduct; hatches in uterus to birth young (ex. boa constrictor) a. Pro – offspring are more advanced in their development when born (compared to live birth); eggs are more protected b. Con – can’t lay as many eggs; also need adequate nutrients for egg (unlike live birth) 3. Viviparity – retains fetus with no egg; young develops in the uterus and gets nutrients from the mother through the placenta (ex. humans) a. Pro – can occur whenever; mother can provide nutrients throughout gestation b. Con – less young (due to need to carry to term); generally longer maturation

Answer 23

1. Cleavage divisions – cell cycles without G1 or G2 phases; only synthesis of DNA and mitosis (not a lot of growth) a. Creates a morula – same size as initial zygote; compact ball of cells 2. Blastulation – morula to blastula a. Blastula – cells organize into single layer; hollow on inside i. May be complicated by amount of yolk 1. Mesolethical - cleavage will not be totally even throughout a. First larger cells produced near yolk of vegetal pole - leads to more cells b. Causes clustering of cells by the yolk - blastula is not totally hollow 3. Gastrulation – blastula to gastrula a. Major reorganization of cells and germ layers b. 3 major events i. Formation of blastopore – first indent/opening in blastula ii. Formation of archenteron - blind ended tube that form GI tract 1. Tube will eventually extend to the other side of gastrula iii. Arrangement of 1. Endoderm – inner 2. Mesoderm – middle 3. Ectoderm – outer c. Mechanisms may vary – results are the same i. Ex. protostome vs deuterostome 4. Neurulation – gastrula to neurula a. Only occurs in chordates – forms hollow nerve chord b. Steps i. Formation of neural plate – derived from ectoderm ii. Folding of neural plate – forms tube and neural crest 1. Neural crest (light blue) – set of cells that migrate around the body to become things like peripheral nerves, part of teeth, skull, etc. iii. Pinching off of tube – neural crest cells detach and diffuse into other parts of body iv. Dorsal hollow nerve chord – becomes spinal cord 5. Organogenesis – formation of organs (human embryo at 11 weeks) a. Endoderm – lines organs within body i. Digestive tract ii. Lungs, urogenital tract b. Ectoderm – outer layer i. Epidermis ii. CNS c. Mesoderm – majority i. Muscles. ii. Skeleton iii. Gonads iv. Kidneys v. Dermis d. Grey area – open space 6. Metamorphosis – larva to juvenile a. Not all animals have larvae i. Advantages – larvae and juvenile/adults don’t complete for the same resources, have different predators, and habitats b. No larval stage (ex. humans) – fill the same ecological niche; no extreme difference between young and adult 7. Growth and maturation – occurs with and without metamorphosis a. Juvenile to adult – reaches sexual maturity (defining feature of adulthood)

Answer 24

Types of chemical signals – bind to receptor  signal transduction  response 1. Autocrine – affect the cell that releases it 2. Paracrine – affects neighbouring cells 3. Endocrine – hormones that travel through the blood 4. Neuroendocrine – hormones released by neurons (go from neuron to blood) Types of hormone structures 1. Polypeptides – water soluble; charged amino acids a. Ex. insulin 2. Amines – water or lipid soluble; modified amino acids a. Ex. catecholamines (NE and E) 3. Steroids – lipid soluble a. Derived from cholesterol

Answer 25

Hormone function 1. Transported via bulk flow – within the blood a. Lipid soluble – more reliant on carrier proteins 2. Bind to receptor a. Membrane bound – water soluble hormones - Can’t move through phospholipids - Faster response b. Cytoplasmic or nucleic – lipophilic hormones - Able to move through the membrane - Slower response 3. Signal transduction – conversion of extracellular signal to intracellular signal 4. Gene regulation – source of control; can turn response on and off 5. Response – elicited by cell Hormone effects 1. Target specific a. Ex. epinephrine – triggers stress response i. Liver – causes release of glucose from glycogen stores ii. Blood vessels – change diameter (vasodilation/constriction) 2. Receptor specific a. Ex. epinephrine – alpha and beta receptors i. Beta – cause vasodilation (ex. in skeletal muscle) ii. Alpha – cause vasoconstriction (ex. in gut)

Answer 26

1. Simple endocrine – one hormone, one target a. Ex. low blood calcium  stimulates parathyroid gland  releases parathyroid hormone i. PTH affects 1. Bones – release ca2+ 2. Kidneys – increase ca2+ reabsorption ii. Increase blood ca2+ iii. Negative feedback – increased ca2+ causes less PTH 2. Neuroendocrine pathway – hormones are released by neuron a. Ex. infant suckling  signal to brain  stimulates hypothalamus  releases oxytocin from neurosecretory cell in posterior pituitary i. Oxytocin 1. Contraction of mammary smooth muscle 2. Milk release ii. Positive feedback – causes more milk ejection 3. Hormone cascades – series of trophic hormones (act on other endocrine glands) a. Ex. response to cold temp i. Brain detects cold temp  stimulates hypothalamus  releases thyroid releasing hormone ii. TRH  stimulates anterior pituitary  releases thyroid stimulating hormone iii. TRS  stimulates thyroid gland  releases thyroid hormones 1. Target body tissues – increases metabolisms to increase body temp iv. Negative feedback – thyroid neg feeds back on TRH and TSH

Answer 27

1. Acute stress – adrenal medulla a. Nerve impulses stimulate – fast activation i. Brain detects  spinal cord  adrenal medulla  NE and E ii. NE and E 1. Increased blood glucose via breakdown of glycogen 2. Increased blood sugar 3. Increased breathing rate 4. Increased metabolic rate 5. Changes in blood flow – directs to heart, brain, skeletal muscle; away from digestive, excretory, and reproductive 2. Chronic stress – adrenal cortex a. Hormones in blood – slower response i. Ant pit releases ACTH  adrenal cortex releases: 1. Glucocorticoids a. Protein and fat breakdown – converted to glucose causing increased blood glucose b. Partial suppression of immune system 2. Mineralocorticoids a. Retention of Na+ and water by kidneys b. Increased blood volume and blood pressure

Answer 28

Prothoracicotropic hormone (PTTH) o Source – brain o Target – prothoracic gland  Releases – ecdysteroid ``` Ecdysteroid o Target – epidermis  2 effects – controlled by JH • Period moulting • Metamorphosis ``` ``` Juvenile hormone o Source – corpora allata in brain o Target – entire body  Response – developmental stage • High JH – ecdysteroid causes moulting • Low JH – ecdysteroid causes metamorphosis (time to be an adult) ```

Answer 29

``` - Sensory neurons – PNS to CNS o Pseudo-unipolar (mostly) o Cell bodies in dorsal root ganglion - Interneurons – entirely in CNS o Connect sensory and motor neurons o Integration – lots of branching of axons - Motor neurons – CNS to PNS o Multipolar ``` Excitable cells - Neurons and muscle fibres - Resting and active states

Answer 30

Resting membrane potential - ~-70mV 1. At rest a. Na+ K+ ATPase i. Primary active transport to maintain neg internal environment WRT outside b. Non gated K+ channels – open and allowing K+ out c. Non gated Na+ channels – open and allowing Na+ in 2. Ion gradients a. Na+ higher outside b. K+ higher inside 3. Stable Vr – there are some fluctuations; is stable as long as AP is not being triggered to open 4. Channels/pumps a. VG na+ closed b. VG K+ closed c. Na+ K+ ATPase – functioning always i. 3na+ out 2k+ in d. Nongated K+ and Na+ leakage channels open i. Relative permeability of K+ is much higher than na+ Active membrane potential 1. Transient depolarization – na+ enters and depolarizes; diffuses to other sections to depolarize those areas (attracted by negative adjacent areas) a. Creates charge reversal across the membrane 2. Types of stimuli – can be sub or suprathreshold a. Tissues damage b. Noxious chemicals c. Neurotransmitters 3. Subthreshold excitation – graded potential a. Proportional to the size of the stimuli b. Will depolarize/hyperpolarize slightly and repolarize to RMP 4. Suprathreshold – action potential a. Not proportional to the size of the stimuli b. All or nothing c. Rapid depolarization 5. Voltage gated ion channels – response to changes in Vm past threshold a. Na+ i. Activation gate – open due to depolarization 1. Immediate – fast opening 2. Will not all open at the same time – a few open at a time ii. Inactivation gate – block at AP peak; ball and chain 1. 5ms delay after na+ open 2. Rapid closing b. K+ i. Activation gate only – no inactivation gate 1. Delayed & very slow – will open at peak of AP when Na+ inactivate ii. 6. AP are static – single AP will occur in one location a. They don’t move – the ions diffuse causing an AP in the adjacent section by triggering VG channels

Answer 31

Action potential 1. Depolarization – opening of VG na+ a. Rapid b. Dominant Na+ influx 2. Repolarization – na+ are inactivated; VG K+ are open a. Dominant K+ efflux 3. Hyperpolarization – na+ are recovering; VG K+ are slow closing a. Na+ are now closed – not inactivated b. K+ efflux continues 4. Repolarization – ATPase re-establishes gradient Refractory periods – ensures unidirectional movement of AP 1. Absolute refractory a. Either all na+ are open or all are inactivated (not closed) b. No stimuli will be able to cause AP 2. Relative refractory a. Na+ are recovering – closed, not inactivated b. Hyperpolarization required larger stimuli AP velocity - Can be increased with 1. Diameter a. Larger = faster 2. Temperature a. Warmer = faster 3. Myelination a. Schwann cells – glia cells; wrap around PNS neurons; insulate b. Nodes of Ranvier – saltatory conduction; allows faster propagation because AP only need to occur at nodes • Saltatory conduction – jumping from node to node • Continuous conduction – no myelin; AP must regenerate along the entire fibre

Answer 32

1. Synaptic cleft – gap between nerve fibres a. Signal changes from electrical to chemical i. Electrical – within neuron ii. Chemical – between neuron 1. Neurotransmitters – released from presynaptic neuron 2. AP triggers CG ca2+ (or another ion) to open – ion enters and causes the release of vesicles containing nt a. Nt – bind to ligand gated channels & causes GP 3. 2 outcomes a. EPSP – nt opens channels that allow positively charged ions to flow into the cell i. Brings post synaptic neuron closer to AP – depolarizing ii. Key to AP = summation of EPSP (temporal or spatial) b. IPSP – nt open channels that allow cl- to enter or K+ to leave i. Brings post synaptic further from AP – hyperpolarizing ii. Common in interneurons – often project back to initial sensory neuron to inhibit signal 1. Negative feedback mechanism

Answer 33

1. Radiata – diffuse net 2. Bilateria – ganglia a. Ganglia – clusters of neuron that do more major processing; can be anywhere in body (not just head) b. Cephalization – clustering of sensory into in the head (anterior end); allows them to navigate their environment (most move head first) 3. Complexity of lifestyle – proportional to brain size & complexity of NS a. Complex integration of sensory info = complex behaviours b. Can be within same animal clade i. Ex. molluscs – flatworm (simple) vs squid (complex) 4. Vertebrate brains are homologous – have evolved from the same major parts/subsections a. Forebrains i. Olfaction – scent ii. Sensory processing iii. Complex coordination – thought b. Midbrain i. Coordinates sensory information – integrates motor and sensory and cognitive performance c. Hindbrain i. Involuntary activities – HR, breathing ii. Vitals Locations of integration 1. Brain (cerebrum) – voluntary control o Sensory input  integration in cerebrum  motor output 2. Spinal cord – involuntary control o Reflexes – hardwired responses to specific stimuli  Can have interneurons (may not)  Can be contralateral or ipsilateral o Ex. knee jerk reflex  Sensory neuron  spinal cord  motor neuron

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1. Sarcomeres – contractile proteins separated z line to z line 2. Contractile proteins a. Thick filaments – myosin i. Aligned at M line – center of sarcomere ii. Myosin heads – attach myosin to actin & pull actin towards M line 1. Hydrolyze ATP to bind b. Thin filaments – actin i. Aligned over z line – ends of sarcomere; actin project towards each other 3. Myofibril – contains end to end sarcomeres a. Muscle fibres – bundles of myofibrils

Answer 35

1. Skeletal muscle a. Striated – actin and myosin organized in sarcomeres b. Contraction i. Sarcomeres – shorten by a few micrometers 1. Up to 100,000 sarcomeres in a series ii. Muscles – will shorten by a few cm due to simultaneous sarcomere contraction c. Voluntary in vertebrates and invertebrates 2. Smooth muscle a. Unstriated – contractile elements are scattered throughout cytoplasm (not organized in sarcomeres) i. Less myosin – dense bodies within cytoplasm ii. More actin – scattered throughout cytoplasm b. Contraction – actin and myosin move past each other and cause non unidirectional contraction i. Invertebrates – involuntary ii. Vertebrates – voluntary

Answer 36

Antagonistic muscle action – work in opposing motions - One contracts – the other relaxes - Ex. circular vs longitudinal muscles in hydrostatic skeleton Types of joints 1. Monoaxial joints – moves in only one plane; a hinge a. Ex. elbow joint 2. Biaxial joint – movement in two axis at right angles to each other a. Ex. knuckles that connect finger to hand 3. Triaxial (universal) joints – can move in any direction; universal movement like a ball and socket joint a. Ex. shoulder 4. Rotational joints – can rotate on a single axis; like a pivot a. Ex. the radium bone next to the ulna

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1. Annelid movement – longitudinal and circular muscles (antagonistic muscle pair) a. Circular – squishes body and allows elongation i. Segment pushes forward b. Longitudinal – pulling the body and shortens i. Segment anchors to the substrate (pushes down into ground when it expands) 2. Nematodes – have only longitudinal a. It both sides contract – body shortens & is not very useful with no opposing muscles b. Contracting one side at a time – gives them swimming motion; curving body to give undulations

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1. Proximate reasons – how they do them; the stimuli & mechanisms; how they are modified 2. Ultimate reasons – why they do them; evolutionary; fitness consequences of behaviour

Answer 39

Causes of behaviour 1. Genetic – nature; intrinsically known a. Ex. birds mating in birds of paradise 2. Learned – nurture; learned from parents or others a. Ex. polar bear cubs learning to hunt from their mom 3. Avoid anthropomorphization – giving human/traits qualities to animals (not driven by the same thing) Can be learned & innate 1. Experiential modification to behaviour a. Ex. white crowned sparrow – show a genetic preference to calls from their own species when looking for mates i. Innate – recognize the calls (genetic control) ii. Learned – doing their species call (environmental control) b. Bird who grew up away from dad with different species – would be innately attracted to white sparrow calls but couldn’t do them 2. Imprinting – sensitive period when they’re very young; long lasting response (years or lifetime) a. Innate – will imprint b. Learned – who they imprint on i. Can be different triggers for different species – ex. first object they see move away from them when they’re born c. Ex. whooping crane – are endangered; got them to imprint on sandhill cranes i. They weren’t able to mate – not a good conservation method d. Ex. getting birds to imprint on kite – can show them good migration patterns e. Ex. salmon – go back to the same place every year

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laid groundwork for behavioural ecology 1. What is the stimulus that causes the response and how a. Proximate – proximate 2. Can experience modify the response a. Proximate 3. How are survival and reproduction improved by the behaviour a. Ultimate 4. How did the behaviour evolve a. Ultimate

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1. response to an external sign stimulus that directs elicits a response 2. Fixed action patterns a. Automatic – doesn’t need to think about it b. Unlearned – nature (not nurture) c. Immutable – unchanging; it will be the same every time d. Unstoppable – once started, they’ll finish 3. Ex. graylag goose – if egg rolls away, they roll it back to the nest with their beak to tuck it back under their nest a. If you remove the egg – they’ll still complete that behaviour

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response to an external stimuli - Can use o Geography – ex. birds will often fly through the same mountain ranges o Sun o Stars o Magnetic fields - Start of migration can be triggered by – photoperiod (day length), temp, food supply o Ex. pine sisken – once the day length changes, they migrate

Answer 43

response to stimuli from others; usually the same species, but sometimes other species Types of communication o Visual, auditory o Chemical ques – olfactory, pheromones o Tactile Ex. dancing honey bees – tell other bees where the food is o Distance to food – number of wiggles during straight part in the middle o Angle of straight part – is relative to the sun - Ex. pheromones in polar bears – males use to track females & mate

Answer 44

1. Spatial learning – environmental ques for location of nest sites, hazards, food, mates a. Ex. digger wasp – test done by Tinbergen i. Wanted to test how they identified nest location 1. Circle of pine cones – they knew nest was there 2. Moving pinecones – followed the circle of pinecones 3. Arranging pinecones in a triangle but rocks in a circle – followed rocks ii. Determined it was the shape of the objects around the nest that ques them iii. 2. Associative learning – stimulus linked to an effect (can be positive or negative) a. Classical conditioning – stimulus is encountered; response is out of animals control i. Arbitrary stimulus associated with a particular outcome ii. Ex. pavlovs dogs – rung a bell before feeding; dogs began to salivate in response to bell b. Operant conditioning – stimulus from an animal’s own behaviour; trial and error learning i. Ex. eating monarch butterflies – they’re easy to see; taste bad 1. Naïve predator – will choose to eat & learn by colour association that it’s gross 3. Cognition – most advanced form of learning; involves awareness, recollection, judgement a. Complex integration i. Sensory information – current input ii. Past experience – to modify current behaviour b. Intelligence = ability to problem solve; process from one state to another i. Novel applications with no previous experience 1. (pattern would be pattern learning) ii. Octopuses – highly intelligent 4. Social learning – observational learning; you see what other members are doing and act the same way a. Young watch older & learn i. Ex. vervet monkeys – distinct alarm call for predators 1. Young – indiscriminate warning calls 2. More experience – will learn distinctive calls b. Common with predators i. Ex. killer whales – stay with parent to learn to hunt instead of trial and error

Answer 45

1. Marginal value theorem – max consumption with minimum cost a. Predator in patch of food (ex. wolf & sheep) – will have an optimal time to travel to a new patch to balance cost & consumption i. Eating more  less food available  more energy to search and catch ii. No food between each patch 1. Will be aware of how much food is in each patch and at what point they should travel to a new patch 2. Optimal foraging – max energy gain with minimal energy expenditure a. Ex. northwestern crows – eat sea snails and shelled animals i. Must break shell by dropping from height 1. Low height – will need to drop multiple times 2. High height – requires a lot of energy to fly up 3. Ideal - ~5m; lowest energy required for max output 3. Altruistic behaviour – freely giving; counter evolutionary; reduces individual fitness but increases fitness of others in population a. Lemmings – do not actually commit suicide; Disney pushed them off cliffs for “documentary” b. No real examples known – except in i. kin selection ii. reciprocal altruism – exchange of aid; occurs in animals that are not related as well 4. Kin selection – animals who share genes may exhibit altruistic behaviours a. Assists in proliferating your own genes b. Ex. vampire bats – will share regurgitated blood to those that didn’t get blood meal i. Will be related to all bats in a roost ii. Reciprocal altruism

Answer 46

1. Competing for resources – food, space, mates a. Threats b. Posturing c. Tests of strength d. Combat – common in males that fight for reproductive access to females; female doesn’t always get to choose 2. Dominance hierarchies – social groups a. Pecking orders i. Ex. alpha males and female wolves – the ones that breed ii. Ex. narwals – lead is the male with biggest tusks (sensory organ; have good sense input) 1. If all males die – female with largest tusks takes over

Answer 47

1. No pair bonds a. Promiscuous – multiple males; multiple females i. Most common in unpredictable environments – hard to tell who has the good genes ii. Often lack social complexity 2. With pair bonds a. Monogamous – one male; one female i. Can be for a year or for life ii. No distinguishing characteristics between male and female – ornamentation b. Polygamous i. Polyandry – one female; multiple males 1. Ex. wilsons falerope – female is more ornamented ii. Polygyny – one male; many females 1. Ex. elk – male is more ornamented iii. Sexual dimorphism – there will be a visible difference is sexes; due to intersexual selection 1. Polygamous – want to be chosen by the other sex 3. Female choice – investing more energy in offspring; often get their choice of male mate a. Preference for phenotypes i. Physical appearance – birds are often brightly coloured ii. Competition winners – common in polar bears iii. Courtship songs – birds iv. Courtship dances b. Imprinting effects – who they imprint on can play a role in who they select later i. Ex. ornamented vs non ornamented dads 1. Ornamented – females were more picky 2. Non ornamented – females were not as picky c. Choice copying i. Social learning plays a role – will choose what other females are choosing 1. Ex. guppies a. Orange = quality male b. Fake female with least orange male  caused other females to select less orange male as well 4. Male-male competition a. Females often only mate once a year – males have a limited number of chances b. Competition i. Brightest, biggest plumage – ex. peacocks ii. Best songs – ex. birds iii. Best territory iv. Agnostic behaviours – ex. fighting 1. Ex. Pata monkeys – males will act aggressively towards young males trying to mate in their social groups