diversity

Question 1

Discuss the taxonomy of microorganisms, plants and animals

Answer 1

Species
Genus
Family
Order
Class
Phylum
Kingdom
Domain ->bacteria, archaea, eukarya(plantae, fungi, protista, anamalia)

based on RNA analysis/nucleic acids, morphology and biogeography

Question 2

animal phyla

Answer 2

Based on morphology and molecular characteristics
Can be classified into major groups(phylum)
* Sponges (Porifera)
* Ctenophores
* Placozoans
* Cnidarians
* Bilaterians
33 monophyletic phyla

Question 3

defining an animal

Answer 3

> 10 mil
Multicellular
Large-bigger than Protozoa
Heterotrophic
Motile
Polarisation along anterior-posterior locomotor axis
Epithelial cells
Ach/cholinesterase
Monophyletic clade-all stem from common ancestor

epithelial cells:
Flexible
Complex shape
Compartmentalise
Anatomical complexity
Waterproofing
Held together with proteins
Allows fluid filled spaces for support and concentration

Question 4

eukarya->anamalia->phylum: (Sponges (Porifera),Ctenophores,Placozoans, Cnidarians, Bilaterians)
SPONGES

Answer 4

N~8,500
Loosely organised
No true organs
No specialised cell layers
Spicules-hard body elements
Choanocytes-feeding cells

Question 5

eukarya->anamalia->phylum: (Sponges (Porifera),Ctenophores,Placozoans, Cnidarians, Bilaterians)
CTENOPHORES

Answer 5

n ~250
* Radial symmetry
* Diploblastic (embryo)
-Ectoderm & endoderm
* Mesoglea – ECM
* Complete gut
* 8 Ctenes (usually)

Question 6

eukarya->anamalia->phylum: (Sponges (Porifera),Ctenophores,Placozoans, Cnidarians, Bilaterians)
PLACOZOANS

Answer 6

N~2 so far
No mouth
No gut
Diploblastic
Contractile fibre cell in the middle
Not well studied

Question 7

eukarya->anamalia->phylum: (Sponges (Porifera),Ctenophores,Placozoans, Cnidarians, Bilaterians)
CNIDARIANS

Answer 7

N~12,500
Jellyfish, sea anemones, corals
Gastrovascular cavity
Typically sessile(polyp) + motile(Medusa) life stages

Question 8

eukarya->anamalia->phylum: (Sponges (Porifera),Ctenophores,Placozoans, Cnidarians, Bilaterians)
BILATERIANS

Answer 8

Bilateral symmetry
Tripoblastic
-exoderm, endoderm, mesoderm

2 major groups
Protosomes
Mouth first-blastopore- mouth opening

Deuterostome
* MouthSecond–blastopore–analopening

Question 9

eukarya->anamalia->bilaterian->6 classes of bilaterian
platyhelminthes(flatworm)

Answer 9

Structurally diverse
May be free living or parasitic
Most of 30k spp are tapeworms/flukes (vertebrae)
Mostly gut endoparasites
A lophotrochozoan (rna)
Taenia asiatica
Schistosoma Spp

Question 10

eukarya->anamalia->bilaterian->6 classes of bilaterian
annelids(leaches)

Answer 10

Segmented worm like bodies
Separate ganglia for each segment
Thin permeable body(gas exchange)
Round body
Lophotrochozoan

Question 11

eukarya->anamalia->bilaterian->6 classes of bilaterian
mollusks

Answer 11

Most diverse lophotrochozoan
Large foot
Main organs in visceral mass
Mantle covers in the visceral mass
Octopus spp
Squid, slugs, snails, muscle, oysters…

Question 12

eukarya->anamalia->bilaterian->6 classes of bilaterian
nematodes(roundworms)

Answer 12

Ecdysozoam group of protozomes
Roundworms-most abundant
Thick, multilayer cuticle(gas exchange)
Un-segmented
Many are predators and parasites
Caenorhabditis elegans
Ascaris lumbricoides

Question 13

eukarya->anamalia->bilaterian->6 classes of bilaterian
chordata

Answer 13

Common features:
Dorsal Hollow nerve cord
Tail that extends beyond the anus
A dorsal supporting rod-notocord

Includes lanceletes, tunicates & vertebrates
-Notochord replaced by supporting structure

Question 14

plant scientists challenges:
 Food security; making food healthier; environmental sustainability; making a green Bioeconomy

FOOD SECURITY

Answer 14

improved yields:
Convention of breeding, selection of yield
Improved agronomy
GM-selecting traits which increase yield

decreased waste:
High income countries
Retail-shelf life, cosmetic appearance
High income countries

Low income countries
Poor food storage
Disease+pests

crops adapted to cope with climate change:
Climate change will drastically affect crop production
Drought resistance
Flooding tolerance
Salt resistance

pest+disease:
Up to 40% of group crop yields are lost to plant pests and diseases each year

Question 15

plant scientists challenges:
 making food healthier; environmental sustainability; making a green Bioeconomy

Answer 15

healthier food:
Improve nutritional value of food
2 bill. People suffer from micronutrients deficiency (golden rice)

environmental sustainability:
Reduce fertiliser and pesticide use(phosphate mining)
Eutrophication
Damage to biodiversity
protecting biodiversity:
Farming has drastic effects on biodiversity
Plants are keystone to nearly all global ecosystems

green bioeconomy:
biofuels:
Fossil fuels-climate change-bad
Oil reserves running out
Plant based replacement for fuel(algae)
bioproducts:
Plants produce a wide range of natural products which could be exploited if we could purify them

Question 16

Taxanomical rank of fungi

Answer 16

Fungi are not plants
Not animals
Kingdom of their own W/5million species

Question 17

 Molecules in fungi

Answer 17

Chitin
Main component of cell wall of fungi
chain formed by N-acetylglucosamine units

Ergosterol
Specific molecule in cell membranes of fungi
in cell membranes of Fungi and protozoa
precursor of vitamin D2
target for antifungal drugs
indicator of fungal presence in soil

Question 18

 Mycelium/Role of hyphae

Answer 18

What are fungi
The fruit body is just the tip
Below is the majority-mycelium

mycelium-An interconnecting series of tubes with rigid walls containing cytoplasm-hyphae

Hyphae roles
Hyphae achieve vegetative spread and absorption of nutrients
They ramify over and within the substratum which is going to be their food source
They can absorb small molecules directly. Large molecules have to be broken down first - they do this by secreting extracellular enzymes
Hyphae are long and thin providing a large surface:volume - ideal for nutrient absorption

Question 19

Fungi food

Answer 19

They do not contain chlorophyll and cannot photosynthesise
(though some can scavenge C from CO2, volatiles etc. under nutrient poor conditions)
They use fixed C in plant and animal materials

compounds fungi use to feed on:
All organic compounds made by plants and animals
Fungi as a kingdom have a vast array of enzymes but not every fungus has all of these enzymes
Fungi vary greatly in their ability to utilize different C sources

Question 20

 Nutritional modes of fungi:
Saprotrophy
Necrotrophy
Biotrophy

Question 21

plant groups: Non-vascular (liverworts, hornworts, mosses)

Answer 21

No xylem/phloem, seeds or flowers
Rely intirely on diffusion
Eg. Liverwort-sexual and asexual reproduction
Mosses

Question 22

plant groups:
 Vascular, seedless (Ferns, lycophytes)

Answer 22

Evolution of xylem and phloem
Allowed much larger plants
Reproduce via spores rather than seeds
Eg. Ferns

Question 23

plant groups:
 Vascular, seeded, non-flowering (Gymnosperms)

Answer 23

Seeds evolved-not flowers
Gymnosperms-800 species

Question 24

plant groups:
 Vascular, seeded, flowering (Angiosperms – monocots vs dicots)

Answer 24

Flowers evolved
Flowering plants-angiosperms
Massive variety in morphology

Monocots-1 cotyledon
Eg. Grasses palms, orchids
Dicots-2 cotyledons
(Broad leaf)
Most leafy crops
Eg. Peas, tomatoes

Either monocots or dicots
Cotyledon-a leaf like structure formed in the embryo