Animal Origins and Diversity

Question 1

4 general characteristics of animals

Answer 1

multicellularity
heterotrophy
internal digestion
motility

Question 2

synapomorphies

Answer 2

shared, derived traits

Question 3

3 synapomorphies of all animals

Answer 3

unique cell junctions between cells- gap junctions
particular extracellular molecules (collagen and proteoglycans)
similarities in developmental genes (hox)

Question 4

sister taxa of animals

Answer 4

choanoflagellates

Question 5

Three key divergences

Answer 5

sponges vs. nonsponges
diploblasts vs. triploblasts
protosomes vs. deuterostomes

Question 6

nonsponges are called

Answer 6

eumetozoans

Question 7

Sponges vs. nonsponges

Answer 7

sponges are asymmetric- no specializaiton in parts. No CNS. Simple and not arrangedcentral channel for individual cells to take up food and oxygen

Question 8

Eumetozoans

Answer 8

have distinct layers of cells formed in early development, nonsponges
split into diploblasts and triploblasts

Question 9

Diploblasts and examples

Answer 9

2 layers
endoderm and ectoderm
jelly fish, coral, placozoa blobs.
Radial symmetry or asymmetrical

Question 10

Ectoderm

Answer 10

outer tube that will become skin and nervous system

Question 11

endoderm

Answer 11

inner tube that will become digestive tract

Question 12

Triploblasts

Answer 12

Have a mesoderm
inner layer that will become muscles, bones, internal organs

Bilaterians
Bilateral symmetry- one plane of symmetry

Question 13

Cephalization

Answer 13

formatinon of head end. sensory structures clustered at anterior end. Comes with bilateral symmetry

Question 14

blastula/blastopore

Answer 14

hollow ball of cells.

hole pakes way up through to form early digestive tract in triploblasts

Question 15

Differentiate triploblasts/bilaterians

Answer 15

protosomes and deuterostomes

Question 16

protostomes

Answer 16

blastopore becomes mouth. mouth first

digestive tract dorsal to nerve cord

Question 17

Deuterostomes

Answer 17

blastopore is anus. anus first

digestive tract ventral to the nerve chord

Question 18

examples of protostomes

Answer 18

mollusks, worms, arthropods

Question 19

Examples of deuterostomes

Answer 19

enichoderms, hemichordates, and chordates (vertebrates)

Question 20

bilaterians

Answer 20

same thing as triploblasts

Question 21

jelly fish (ctenophora) and coral (cnidara)

Answer 21

diploblasts with rudimentary nervous system

Question 22

placozoa

Answer 22

diploblasts; simplification- loss of nervous system