Animals

Question 1

Which eukaryotic domain are animals in?

Answer 1

Unikonta: Opistikonts

Question 2

what are animal’s closest relative

Answer 2

choanoflagellates

Question 3

9 characteristics of animals

Answer 3

1. heterotrophic
2. cells lack cell walls
3. multicellular eukaryote with tissues that developed from embryonic layers
4. reproduce sexually with diploid stage dominating
5. blastula undergoes gastrulation resulting in the formation of embryonic tissue layers and gastrula
6. germ layers
7. cell specialization
8. tissue held together by structural proteins like collagen
9. HOX family of genes

Question 4

protostomes

Answer 4

first mouth= blastopore became mouth
cleavage is spiral and determinate
solid masses of mesoderm split and form coelom

Question 5

deuterostomes

Answer 5

second mouth= blastopore became anus
cleavage is radial and indeterminate
folds and archenteron form coelom

Question 6

Tissue

Answer 6

Tissue: collection of specialized cells isolated from other tissues by membranous layer
- ectoderm: germ layer covering the surface of embryo
- endoderm: inner most layer and lines what the digestive tube (archenteron) will be
- mesoderm: middle layer that gives rise to muscles and organs
- diploblastic: 2 layers
- triploblastic: 3 layers

Question 7

Coelom (body cavities)

Answer 7

a fluid filled body cavity derived from mesoderm in between the digestive tract and outer body wall
- coelomate: animals that possess a true coelom
- pseudocoelomate: have the space but no attachment linking wall and digestive tract
- acoelomate: no coelom

Question 8

Body Symmetry

Answer 8

• radial: multiple cuts are made, Allows organism to meet environment from all sides so circular usually
• bilateral (two sided): have a dorsal/ventral, left/right, anterior/posterior, bilateral allows cephalization which is the development of a head
• asymmetry: sponge

Question 9

Cell division that leads to embryonic layers and gave rise to diff tissue types

Answer 9

• After a sperm fertilizes an egg the zygote undergoes cleavage, leading to the formation of a blastula. The blastula undergoes gastrulation resulting in the formation of embryonic tissue layers and a gastrula. The tissue layers then give rise to germ layers that there could be 2 or 3 of

Question 10

flagellum

Answer 10

how choanoflagellates swim