Animals I

Question 1

What kind of life cycle do all animals have?

Answer 1

Diplontic (2n dominant) life cycle

Question 2

When did the earliest animals arrive?

Answer 2

600 mya

Question 3

(T/F) All animals are multicellular.

Answer 3

True

Question 4

(T/F) All animals are chemoheterotrophic.

Answer 4

True

Question 5

Animals are sister group to __________?

Answer 5

Choanoflagellates

Question 6

Define gastrulation.

Answer 6

The process in which an undifferentiated blastula develops into an embryo with 2 or 3 tissue layers

Question 7

(T//F) All animals undergo gastrulation.

Answer 7

False. Only Eumetazoans do.

Question 8

Name five GENERAL characteristics of animals (remember, these characters are not unique to animals. Other living things may exhibit these traits)

Answer 8

1. multicellularity
2. oogamy
3. chemoheterotrophy
4. internal digestion
5. movement

Question 9

Name 2 synapomorphies of animals (unique to animals)

Answer 9

1. unique junctions between cells
2. Extracellular matrix

Question 10

(T/F) All Eumetazoans are triploblastic.

Answer 10

False. They can be diploblastic as well.

Question 11

Name the difference between diploblastic and triploblastic

Answer 11

Triploblastic animals have a mesoderm and a mouth

Question 12

What does the endoderm give rise to

Answer 12

lining of the digestive tract, respiratory tract, pancreas, and liver

Question 13

What does to ectoderm give rise to

Answer 13

The nervous system, including eyes and ears, and the epidermal layer of skin

Question 14

What does the mesoderm give rise to

Answer 14

organs like the heart, blood vessels, muscles, and bones

Question 15

At the 8 cell stage, name differences in cleavage between Protostomes and Deuterostomes.

Answer 15

Protostomes have spiral and determinate cleavage, while deuterostomes have radial and indeterminate cleavage

Question 16

Compare the mesoderm between Protostomes and Deuterostomes

Answer 16

Protostomes- schizo. Mesoderm splits into two to form coelom
Deuterostomes- enterocoleous: Folds of archenteron form into a coelom

Question 17

What happens to the blastopore of a Protostome vs a Deuterostome

Answer 17

In protostomes, the mouth develops from blastopore. In deuterostomes, the anus develops from blastopore.

Question 18

Name an example of a pseudocoelmate animal.

Answer 18

Roundworms. Rotifers. Nematodes.

Question 19

Name the 3 groups of Diploblastic animals

Answer 19

Cnetophores, Placazoans, Cnidarians

Question 20

Sponges have a jelly like ______ between epithelial layers

Answer 20

mesophyl

Question 21

Sponges food is captured by ________ and digested using ________ cells.

Answer 21

Choanocytes, ameboid

Question 22

Diploblastic animals have _______ nervous systems called “______ ______”

Answer 22

simple, nerve nets

Question 23

Why are Cnetophores considered to be more basal than the other two diploblast groups?

Answer 23

Placazoans and Cnidarians have HOX-like genes

Question 24

(T/F) Cnetophores have HOX-like genes.

Answer 24

False

Question 25

(T/F) Cnetophores have complete guts.

Answer 25

True

Question 26

Cnetophores (aka comb jellies) are different from jellyfish how?

Answer 26

They have 8 rows of cilia bearing plates

Question 27

(T/F) Placazoans are flat animals with no mouth, gut, or nervous system

Answer 27

True

Question 28

(T/F) Placazoans digest their food externally

Answer 28

True

Question 29

Cnidaria are characterized by stinging cells called what?

Answer 29

nematocysts

Question 30

Cnidaria are sister to what group?

Answer 30

Bilaterans

Question 31

(T/F) There are non predatory Cnidarians

Answer 31

False

Question 32

Name the subcellular structure that Cnidarians have to sting their prey

Answer 32

cnidocytes

Question 33

Describe the Cnidarian life cycle

Answer 33

Alternation of medusa and pokyp stages

Question 34

What is the purpose of a body cavity (being coelmate)?

Answer 34

It helps the animal be more flexible, and isolates organs from the wall of the body.

Question 35

The body cavity of coelmate animals develops within the ______

Answer 35

mesoderm