Lecture 29 - History of Animal Life on Earth

Question 1

What domain are animals in?

Answer 1

Eurkarya

Question 2

Are animals multi or uni cellular?

Answer 2

multicellular

Question 3

What are animals held together by?

Answer 3

collagen

Question 4

Do animals have cell walls?

Answer 4

no

Question 5

How do animals reproduce?

Answer 5

sexually

Question 6

Which stage is the dominating stage of the lifecycle in animals?

Answer 6

diploid stage

Question 7

What are the 5 basic stages of sexual reproduction/

Answer 7

1. fertilization
2. zygote
3. cleavage
4. blastula
5. gastrula

Question 8

What specialized genes do animals have?

Answer 8

hox genes

Question 9

What are the 5 characteristics of an animal?

Answer 9

1. Multicellular, heterotrophic eukaroytes
2. Lack cell walls of plants + fungi
3. Two unique tissues: nerves + muscles
4. Sexual reproduction, diploid adult stage
5. Have homeotic (Hox) genes regulating early development

Question 10

What are larva?

Answer 10

• sexually immature

- morphologically/ecologically distinct from adult

Question 11

Larvae eventually undergo __________

Answer 11

metamorphosis

Question 12

What are the 2 types of symmetry?

Answer 12

1. Radial (diplobaslatic)

2. Bilateral (tripoblastic)

Question 13

What are the 3 germ layers?

Answer 13

1. ectoderm
2. endoderm
3. mesoderm (only in tripblastic)

Question 14

What are 2 types of development?

Answer 14

1. protosome (spiral)
   - blastopore becomes mouth
2. deuterosome
   - blastopore becomes anus

Question 15

What is the common ancestor for all animals?

Answer 15

choanoflagellates

Question 16

What are the 3 types of body cavites?

Answer 16

1. coelomates (true cavity derived from mesoderm)
2. pseudocoelomates (derived from mesoderm + endoderm)
3. acoelomates

Question 17

What may have been the first vertebrates to leave water?

Answer 17

lungfish relatives

Question 18

What are the 4 major Eras?

Answer 18

1. Neoproterozoic
2. Paleozoic
3. Mesozoic
4. Cenozoic

Question 19

What was the neoproterozic era?

Answer 19

• First evidence of early animal embryos + predation

- included Ediacaran

Question 20

What was the main feature of the paleozoic era?

Answer 20

Cambrian Explosion

-earliest fossil appearance of many major groups of living animals

Question 21

What are 3 reasons for the Cambrian explosion?

Answer 21

1. hox genes
2. oxygen
3. predation

Question 22

What are 3 defining features of the mesozoic era?

Answer 22

1. Coral reefs
2. Dinosaurs were dominant terrestrial vertebrates
3. First mammals emerged, flowers/insects diversified

Question 23

What are 3 defining features of the cenozoic era?

Answer 23

1. Mass extinctions of both terrestrial + marine animals (nonflying dinosaurs, marine reptiles)
2. Diversifications of mammals
3. Global climate cooled