T16

Question 1

invertebrates vs vertebrates

Answer 1

invertebrataes = no backbone - majority of animals are

vertebrates = backbone

Question 2

diploblastic

Answer 2

2 layers are formed during development, after gastrulation

endoderm and ectoderm

include jellyfish/cnidaria

no mesoderm

Question 3

triploblastic

Answer 3

3 layers form, endoderm,ectoderm, mesoderm

a tube forms - two types of these, protosome or a deuterostome

Question 4

protosome

Answer 4

includes - molluscs, annelids, arthropods

In the eight cell stage of development, cells are spiral, no symmetrical, have a development direction - which means cannot split the cell in half and have 2 identical embryos

the blastopore develops into the mouth

Question 5

deutrosomes

Answer 5

in eight cell stage - radial, symmetrical, and not determined in development direction so the cells can split in half and form an identical embryo- twins

the original blastopore becomes the anus

Question 6

body cavity - coelom

Answer 6

it is a space or fluid that separates the digestive tract from the outer body wall- between the endo and ectoderm

Question 7

what function does a body cavity have?

Answer 7

• it cushions organs to prevent injury
• organs can be suspended so can move independently
• allows room for organs to grow
• can be filled with non-compressible fluid in hydrostatic skeletons

Question 8

true coelom - coelomate

Answer 8

the body cavity - space is completely lined by tissue from the mesoderm

Question 9

false coelom - psuedocoelomate

Answer 9

body cavity lined by the mesoderm and the endoderm

Question 10

no coelom - acoelomates

Answer 10

no body cavity at all - just goes undo,meso,ecor

Question 11

radial symmetry

Answer 11

top and a bottom
- no left or right

Question 12

bilaterial symmetry

Answer 12

top and bottom, left right, front and back

Question 13

Porifera - sponges

Answer 13

first separation in the metazoa tree
- no symmetry
- no gut
- no germ layers - no cleavage pattern in development

-mainly marine
-a basal group of animals
-choanocytes - create water current for filter feeding
- sexual or asexual
- fiercely competitive for space
- can reform from constituent parts because they are so simple

Question 14

Cnidaria - jellyfish, coral

Answer 14

in the eumetoza group
- diploblastic
- radial symmetry - related to sediternary lifestyle
- have specialised stinging cells called cnidocytes
- polyp - sessile - stationary - coral
- medusa - motile - jellyfish

Question 15

lophotrochozoa - protostomes

Answer 15

triploblastic
- lophphore feeding appartus or trochophore larva

includes annedlida, mollusca, brachiopoda, platyhelminthes, syndermata

Question 16

platyhelminthes

Answer 16

flatworms
- simple body no body cavity,
-have nerves
- reproduce asexually or sexually
- many are parasites

Question 17

annelida

Answer 17

segmented worms
- extremly diverse
- triploblastic
- sedentria - warm leeches - slower and sedentary
- errantia - marine and very motile with parapodia - leg like appenditches

Question 18

mollusca

Answer 18

slugs, snails. clams, squid, octopuses
-very diverse, found in all habitats

Question 19

mollusc basic body plan

Answer 19

mantle - mantle cavity where organs are kept
- heart - pumps fluid called hemolymph
- metanephridium - excretory organs
- nervous system - ring of nerves around esophagus
- at the mouth, have radula as teeth to scrape food

Question 20

brachipoda

Answer 20

purely marine filter feeders with a complete gut
- have upper and lower shells
- possess unique stalk to anchor to subtrate
- have lophahore feeding system

can be classed as articulate or inarticulate

Question 21

ecdysozoa - protosomes

Answer 21

moult their cuticles periodically
include - arthropds, nematoda, tradigradas, onychorphroa

are triploblastic- complete gut

Question 22

onychophoran

Answer 22

velvet worms
- purely terristrial with marine ancestors
- peripatidae - equitorial regions
- peripatopsidae - southern regions

are pseudocoelomates - have hydrostatic skeletons
- sexual and dioecious

Question 23

dioecious

Answer 23

having the male and female reproductive organs in separate individuals.

Question 24

TARDIGRADA

Answer 24

water bears
- most in fresh water or semiaquatic
- small, eight legged and hardy
- gained many genes from horizontal gene transfer

Question 25

arthropoda

Answer 25

most animals , jointed legs
- segmented body
- hard exoskeleton
- all habitats
- digestive tact but has open circulatory system

includes 3 major divisions
- chelicerates - spiders, mites, scropions
- myrciapods - millipedes, centipedes
- pancrustaceans - insects, crabs

Question 26

NEMATODA

Answer 26

all habitats
- pseudocoelomates
- no circulatory system
- digestive tract
- dioecius

Question 27

deutrerostomia

Answer 27

include echinodermata, chordata, hemichordata

triploblastic
deuterostomes
true coelom

Question 28

echinodermata

Answer 28

sea urchins, sea stars, spiny skin
-slow moving or sessile marine animals
- epidermins covers exoskleteon
- tube feet powered by hydraulic water pressure
- dioecious
- bilateral symmetry in larvae

Question 29

hemichordata

Answer 29

• marine burrow dwelling
• no central nervous system, nerve in tissue concentrated in the collar
• share traits with chordata

Question 30

chordata

Answer 30

to be continued …