Diversity! (Core) Flashcards
(111 cards)
1
Q
What are some common characteristics of the animalia kingdom? (8)
A
- multicellular organisms (then organised into tissues, epithelia etc)
- Heterotrophic- receive energy from consuming other life forms
- Large (bigger than protozoa)
- Motile (part/all post embryonic, organisms capable of locomotion)
- Polarisation along anterior posterior locomotory axis
- Epithelial cells
- Acetylcholine/cholinesterase system
- Monophyletic clade (family composed from a common ancestor)
2
Q
Who is the father of classification?
A
Carolus Linnaeus
3
Q
What are the names of the major animal phyla?
A
Sponges (porifera)
Ctenophores/ comb jellies
Placozoans
Cnidarians
Bilaterians (consists of Protosomes and Deuterosomes,
then protosomes can further subdivide into Flatworms (platy), Annelids, Molluskcs, Nematodes and arthropods)
4
Q
What is the relative group size of sponges (porifera)
A
Around 8500sp, not too shabby
5
Q
Name some of the physical characteristics of sponges
A
Loosely organised internally (no true organs)
No specialised cell layers
Spicules (hard body elements that when meshed provide structural support)
Choanocytes- specialised ciliated feeding cell which acts as a feeding filter, only absorb useful nutrients in water. is a round cell body lined with microvilli around a central flagellum
6
Q
what sort of niche do sponges occupy?
A
Porifera are ESSENTIAL in reefs, filter water around them (using choanocytes)
7
Q
relative group size of ctenophores
A
200 sp. quite weeny.
8
Q
physical characteristics of ctenophores
A
- Exhibit radial symmetry.
- Diploblastic (where cells are arranged in two embryonic layers-ectoderm and endoderm)
- Mesoglea (extracellular matrix, like a jellylike substance) that acts as a hydrostatic skeleton
- They have a complete gut, with mouth and anus.
- Usually have 8 ctenes (locomotor organs consisting of a row of strong cilia with fused bases)
look like a vagina
9
Q
what sort of niche do ctenophores occupy
A
Help control populations and maintain biodiversity across plankton communities. In all areas of the world’s seas, but prefer warm waters and near the top, like the east coast of the Americas.
10
Q
relative group size of placozoans
A
25-100sp so far! not well studied
11
Q
physical charcteristics of placozoans
A
No mouth or gut but are diploblastic (body derived from only 2 embryonic cell layers). Have a contractile fibre cell in the middle.
12
Q
What is the placozoan niche?
A
Tropical Shallow marine environments, on surfaces of submerged rocks, corals, mangrove roots. Abundant in marine systems and lots in aquariums
13
Q
Give the relative group size of cnidarians
A
around 10K species
14
Q
physical characteristics of cnidarians
A
- They have a gastrovascular cavity (responsible for both digestion and transport of nutrients through body. Two-way digestive tract.).
- Typically exhibit both sessile (polyp, tubular body) and motile (medusa, bell shaped) life stages.
- Have specialised cell types called Nematocysts - large organelles produced from the Golgi apparatus as a secretory product within a specialised cell. Can be used for locomotion but also act as a defense against predators, where they deliver a sting.
“pressurised capsule containing a coiled harpoon like thread”.
15
Q
What is the cnidarian niche
A
Jellyfish, sea anenome and coral.
Occupy two major niches.
Using their cnidocysts to entrap prey, some depend on zooxanthellae, symbiotic dinoflagellates within the tissues, to survive.
16
Q
what is a bilaterian?
A
- Just describes organisms that have bilateral symmetry.
- Triploblastic (three germ layers of ectoderm, endoderm, mesoderm).
Two major groups of bilaterians
17
Q
what are the two major groups of bilaterians?
A
Protosomes (mouth formed first then blastopore, mouth)
Deuterosomes (anus developed from blastopore then mouth second)
18
Q
Give the 5 types of protostomes
A
Platyhelminths (flatworms)
Annelids
Molluscs
Nematodes
Arthropods
19
Q
tell me about platyhelminths (who actually gives a duck im actually gonna crash out)
A
- Structurally diverse
- May be free living or parasitic.
- Most of the 30k species are tapeworms/flukes (vertebrates).
- Mostly gut endoparasites.
- Lophotrochozoan RNA.
Important for humans e.g Taenia Asiatica, - one in 5 people infected very common human parasite and is caught from eating undercooked pork.
another example: Schistosoma/blood flukes Spp part of flatworm, - cause schistosomiasis disease, second only to malaria in terms of morbidity, 10 million affected, lots of people and vertebrates affected. Acute and chronic parasitic disease.
20
Q
Tell me about annelids pretty please xoxo
A
- Segmented wormlike bodies (20k spp)
- separate ganglia for each segment,
- thin permeable body to help with gas exchange, lophotrochozoan.
21
Q
what the literal helly is a lophotrochozoan i keep seeing it written down im so confused
A
Lophotrochozoa is a monophyletic group of protosome animals that comprise annelids, molluscs, brachiopods, moss animals (bryozoans), flatworms (platyhelminthes), and their relatives
- triploblastic
- free living larval stage
- ciliated
22
Q
describe molluscs
A
- Most diverse lophotrochozoan, large foot
- Main organs in a visceral mass
- Mantle (fold of tissue) covers the visceral mass
- 50k-200k spp
e.g Squids, slugs, snails, mussels and oysters
23
Q
describe nematodes
A
- Roundworms, ecdysozoan (group of protosomes)
- Roundworms most abundant
- 3 layered cuticle which they shed as they grow so they can get bigger
- Thick multilayered cuticle, gas exchange (also with gut).
- Unsegmented (contract body to move)
- Many are predators and parasites, e.g Caenorhabditis elegans (transparent), Ascaris Lumbricoides (human parasite, in over 2 billion worldwide 1 in 4, more in subtropical & tropical areas.),
- Millions of spp
24
Q
describe arthropods
A
- Ecdysozoans
- Diverse (1-10mil spps) and numerous
- Name means jointed limb
- Segmented bodies
- Exoskeleton of chitin (waterproofing), muscles on the inside
- Jointed and specialised appendages.
‘To good approximation, all species are insects. By far the most abundant phyla of animalia.’
25
what are ecdysozoans
Ecdysozoa is a group of protostome animals, including Arthropoda, Nematoda, and several smaller phyla.
- they have a cuticle that they shed and molt
26
characteristics of deuterosomes (chordata)
- Dorsal hollow nerve cord
- Tail that extends beyond the anus
- A dorsal supporting rod- notochord
- Includes lancelets, tunicates and vertebrates (notochord replaced by supporting structure)
Approx. 70k spp
| humans are chordates!
27
what is the main component of cell walls in fungi?
chitin
28
What was the green revolution
- Using dwarf wheat to double food yields in India and Pakistan
- Reduced height of crops
- Saved over a billion lives
29
What is golden rice?
High levels of beta carotene (a vitamin A precursor) to prevent blindness due to VitA deficiency
## Footnote
~750,000 children go blind every year from vit a deficiency
30
Plant based replacement for fuel?
Algae and Miscanthus
31
What is plant plasticity?
Possible for plant cells to undifferentiated and re-differentiate
- can regenerate whole plants from almost any piece of tissue
32
How to do tissue culture (micropropagation)
- Get Explant
- Agar plate on petri dish + cytokinins and auxins, different ratios
- Callus
- Split
- Plantlets
33
Are algae plants?
No
34
What are embryophytes?
True plants
35
What are 3 non-vascular plants?
Liverworts
Hornworts
Mosses
36
What allowed the development of vascular plants?
Evolution of xylem and phloem
37
What are gymnosperms?
Plants with seeds but no flowers
- Gymnosperms about 800 species
- E.g ginko tree, cyads, conifers
## Footnote
Vascular plants!!
38
What are angiosperms?
Plants with flowers
- Nearly 400,000 species
- Angiosperms are either monocots or dicots
- Evolved only about 300 million years ago
- Massive variety in morphology
39
What are monocots vs dicots?
- Monocot: one cotyledon (e.g grasses, palms, orchids) great biomass, all major crops, one leafed, cereal crops
- Dicot: two cotyledons, broad-leafed plants, 2 leafed, most leafy crops
40
what are the 2 types of pollination? how are plants adapted for this?
Wind
- Flowers structured for dispersal
- Common method in monocots
- Large quantities of pollen
Animal
- Usually insects
- Brightly coloured structured
- Attractive
- Benefit e.g nectar
41
how many species of fungi?
over 5 million
42
What are fungi cell walls made of?
Chitin formed of N-acetylglucosamin units
43
what are the main components in fungal cell membranes?
Ergosterol:
- Specific molecule that makes up cell membrane
- Precursor for vitamin D2
- Target for antifungal drugs
- Indicator of fungal presence in soil
44
What are fungi?
**Fruiting body** with **mycelium** underground connected by series of tubes with rigid walls containing cytoplasm called **hyphae**
45
what is mycelium made of?
- Consists of network of tubes
- Rigid walls containing cytoplasm
- Termed HYPHA
- Plural = hyphae
- Arises from a germinating spore.
46
role of hyphae?
- Achieve vegetative spread and mass absorption of nutrients.
- Respond to needs of system: will adapt to environment and still maintain life for overall fungus
- Long and thin to provide a large surface area to volume ratio for nutrient absorption
- Hyphae usually spread away from each other, to optimize area explored for capture of nutrients
47
What is the difference between mycelium and hypha?
Mycelium is the overall structure composed of hyphae.
- Hyphae = individual
- Mycelium = network of hyphae
48
What does apical growth mean in the context of the hyphae?
They mainly extend from the tips rather than the base
49
What is the name given to the aggregate linear organ that achieves vegetative spread?
Cords rhizomorphs
50
What is the name given to the walls within the hyphae? In which organisms do these occur in? What does it allow?
- Hyphae are divided into compartments by septa
- This happens in higher fungi
- This allows the production of complex fruit bodies
51
What are the 3 nutritional modes fungi employ?
1. Saprotrophy - dead plant and animal tissue
2. Necrotrophy - kill and use before, during, and after death
3. Biotrophy - living tissues (parasitic - harmful, mutualist - beneficial)
52
what is saprotrophic nutrition?
- Breaking down complex organic material externally using enzymes and absorbing the simpler products
- They use C in plants and animals as don't have chlorophyll so can't photosynthesise
-feeding off of dead organic matter
53
What are the roles of saprotrophs?
- Nutrient cycling
- Nutrient transformation
- Humus formation
- Soil structure and stability
54
What is the main difference between white and brown rot?
White rot uses all components of the material including the lignin (it can therefore completely decompose wood), whereas brown rot can only use simple compounds
## Footnote
Also brown rot is brown and white rot is white lol
55
What can be said about the rate of decay by soft rot? What about the environmental conditions it requires?
- Soft rot decays material much slower and less extensively
- It occurs mainly in wet and fluctuating moisture conditions
## Footnote
Simple compounds (some can do lignin removal but its quite shit)
56
What is the phrase used to describe how necrotrophs kill those they infect
'damping off'
57
how do hyphae grow to form mycelia?
Hyphae grow from the tip APICAL, they diverge, side branches form, fill the gap. Diverging hyphae with tangential connections to form networks (mycelia)
Hyphae aggregate to form fruit bodies and tissues
Mycelium arises from a germinating spore - atypical growth
58
how can complex fruit bodies form in mycelia?
In higher fungi the tubes are divided into compartments by cross walls called septa. This allows differentiation or different activities to occur within the mycelium, which can result in complex fruit bodies.
59
What are septa?
Compartments, not cells
Can have clamp connections form around them
60
what are sclerotia?
Usually, hyphae spread away from each other to optimise the area explored for nutrient absorption, however they sometimes aggregate to form fruit bodies and other tissues/organs like SCLEROTIA.
## Footnote
they are balls of hyphae with a thick protective rind, to withstand harsh conditions.
61
What are nematocysts?
Stinging cells found in Cnidarians
62
What are pseudosclerotial plates?
Thin plates of tissues that surround decaying bodies and protect a fungus from its neighbour
## Footnote
pseudosclerotia are are balls or plates of hyphae with additional animal or plant proteins
63
what are rhizomorphs?
They can aggregate to form linear organs which achieve vegetative spread (rhizomorphs)
64
Which phyla are diploblast?
Cnidaria
Ctenophores
Placozoans
65
what do fungi feed on? what compounds can they use and why is this important?
Because they do not contain chlorophyll and thus cannot photosynthesise, they use FIXED CARBON in plant and animal materials.
All organic compounds are produced by animals and plants.
Fungi vary greatly in their ability to utilize different carbon sources,
This is important in nutrient cycling, nutrient translocation
66
What are lophotrochozoans?
Lophotrochozoans = "protostomes with either a lophophore (feeding) or trochophore larva (development)."
Include molluscs, annelids, flatworms, and more.
Part of the Bilaterians → triploblastic, bilateral symmetry
Protosomes
67
What are 3 fungi nutritional modes?
Saprotrophy
Necrotrophy
Biotrophy
68
What is saprotrophy?
Using organic molecules from dead plant and animal tissues
69
What is necrotrophy?
Using organic molecules by killing and using before, during and after death
70
What is biotrophy?
Using organic molecules from living tissues
- harmful to plant - parasite
- beneficial to plant - mutualist
71
What are the roles of saprotrophs?
- Nutrient recycling
- Nutrient translocation
- Humus formation
- Soil structure and stability
72
Give the 4 types of wood rot in saprotrophs
stain
brown rot
white rot
soft rot
73
what is stain wood decay?
caused by fungi that feed on wall tissues (ascomycetes)
74
what is brown rot
mainly basidiomycetes. brown crumbly appearance, hyphae lie on cell wall in lumen. simple compounds, cellulose and hemiocellulose are used by fungus! lignin not used. h202 diffuse into wall.
75
what is white rot
fungus uses all components, including lignin. white fibrous appearance, hyphae lie on cell walls in lumen, forms erosion grooves which coalesce.
can completely erode wood to co2 and h20.
76
what is soft rot
simple compounds, cellulose and hemicellulose are used.
lignin removal is either absent or slow and unfinished.
wood cell wall breakdown is in immediate vicinity of hyphae.
decay is slow and not so extensive
-important in wet and fluctuating moisture conditions
- type 1 occurs in S2 layer producing cavities
- type 2 occurs in lumen giving erosion grooves
77
what are necrotrophs
KILLERS!!!!!!!
kill by enzymes and cause damping off (causes emerging seedlings to collape, submerged in a mass of white fungal growth)
- creates lesions due to toxins which spread
- causes vascular wilts
- some kill invertebrates so can be used instead of pesticides
78
what is vascular wilt?
Disease! necrotrophs infect xylem tubes, proliferate and prevent water and mineral trasnport, causes a blockcage and causing plant to wilt and die. they enter plant, secrete toxins and cause lesions to form, damaging the plant,.
e.g e.g dutch elm disease – vascular tissues in a plant blocked so plant dies
and ashdieback
79
what are biotrophs?
1. MUTUALISTS! Lichen. intimate relationship between photobiont and mycobiont (cyanobacteria)
beneficial
2. Parasites
- Grows on plants and keeps it alive but taking nutrients for itself
- E.g rust, smuts and mildews
- Intimates relationship with host
- Tend to keep plant alive longer so fungus can survive
- E.g green islands
80
what is lichenization and why is it important
Lichenization is the strategy of symbiotic tropically specialized fungi (mycobionts) that obtain carbon from their photobionts (green algae and or cyanobacteria).
Important in very extreme environments. Useful for monitoring pollution (e.g. If you increase atmospheric N, then there will be an increase in n-tolerant lichen species growing on bark).
81
describe mycorrhizas
Mutualists, Mycorrhizas! Plants depend on fungi to form symbiotic relationships with roots, they act as extensions of the root and increase absorbative area of the plant, extensions of root system.
-----
so mycorrhizas are the hairdressers that give plants hair extensions
82
What kingdoms were initially proposed by Linneaus?
Animals
Plants
Minerals
83
What did Hogg and Haeckel propose?
Addition of protists and eukaryotic microorganisms
Removal of minerals
84
What did Whittaker propose?
The 5 kingdoms:
Bacteria, protists, fungi, plants, animals
85
What did Woese propose?
The 3 domains through **rRNA analysis **
The new kingdoms
86
How do ecdysozoans grow?
Moult outer shell
E.g. nematodes, arthropods
87
What are the 3 common features of chordata development?
Dorsal hollow nerve cord
Tail that extends beyond the anus
A dorsal supporting rod – notocord
88
What groups do protosomes split into?
Lophotrochozoans
Ecdysozoans
89
What groups do bilaterians split into?
Deuterostomes
Protostomes
90
What plant was involved in the green revolution in 1970s?
Dwarf wheat
91
Explain plant plasticity
It is possible for plant cells to undifferentiated then re-differentiate
You can regenerate a whole plant from almost any piece of tissue
92
Are algae plants?
No - embryophytes are true plants
93
Give 3 examples of non-vascular plants
Liverworts
Hornworts
Mosses
94
How do lycophytes reproduce? And ferns etc.
By spores - they are pre seed vascular plants
95
What are the 2 kinds of seed plants?
Gymnosperms
Angiosperms
96
What are angiosperms split into?
Dicots
Monocots
97
What is a cotyledon?
A leaf-like structure formed in the embryo
98
What do dicots generally look like?
Broad leafed plants
99
Give 2 examples of fungi phyla
Basidiomycota (e.g., mushrooms)
Ascomycota (e.g., morels, truffles)
| in the subkingdom dikarya
100
What are fungal cell walls made out of?
Chitin
101
What are fungal cell membranes made out of?
ergosterol
102
What is the mycelium made out of? The broad structures
Hyphae
Septa
103
What is ergosterol a precursor for?
Vitamin D2 - therefore this is an indicator of fungal presence in soil
104
What is the role of the hyphae?
Nutrient absorption: Huge surface area to volume ratio.
Secretes extracellular enzymes: Breaks down large molecules (like cellulose) into small, absorbable ones.
Spreads across and within the food source
105
How does the mycelium grow?
Apical growth from germinating spores
106
What do septa allow for?
Differentiation across the hyphae
107
What are the 3 feeding methods of fungi?
Saprotrophs: Feed on dead material (decomposers).
Necrotrophs: Kill host and then feed on it.
Biotrophs: Feed on living host (can be parasites or mutualists).
108
What kind of feeders cause wood decay?
Saprotrophs
109
Describe the 3 kinds of wood decay
Brown rot: Breaks cellulose, not lignin; leaves wood brown and crumbly.
White rot: Breaks everything, including lignin; leaves wood white and fibrous.
Soft rot: Slow, less extensive decay; important in wet conditions
110
What do necrotrophs cause in their food?
Cause diseases like damping off, vascular wilts, rusts, and smut
111
Give 2 examples of mutualist biotroph fungi
Mycorrhizas
Lichens
