Chapter 32- Overview of Animal Diversity

Question 1

What are the 5 key transitions in animal evolution?

Answer 1

1. ) Tissues
2. ) Symmetry
3. ) Body Cavity
4. ) Development
5. ) Segmentation

Question 2

Define Tissues

Answer 2

Closesly associated, similar or identical cells that work together to perform one or more functions

Question 3

Define Organs

Answer 3

Discrete body part composed of several tissue types that performs one or more functions

Question 4

Organ system?

Answer 4

Several organs that work together to perform one or more functions (circulatory system)

Question 5

What are the two types of animals as defined by tissues

Answer 5

Parazoa-sponges, lack defined tissues and organs

Eumatozoa-all other animals

Question 6

What are the two main types of symmetry in animals?

Answer 6

Radial symmetry

Bilateral symmetry

Question 7

What is Radial Symmetry

Answer 7

Body parts arranged around central axis

-Can be bisected into two equal halve in any 2d plane

Question 8

Bilateral Symmetry

Answer 8

Body has right and left halves that are mirror images; adaptation for motile life

Question 9

What are the 2 advantages bilateral animals have over the radially symmetrical ones

Answer 9

Cephalization

Greater mobility

Question 10

What is cephalization

Answer 10

evolution of a definite brain area; contains most sensory apparatus

Question 11

What is the ectoderm

Answer 11

The outer germ layer-body coverings and nervous system

Question 12

What is the mesoderm

Answer 12

The middle germ layer; skeleton and muscles and many internal organs

Question 13

What is the endoderm

Answer 13

the inner germ layer; The digestive organs and intestines

Question 14

What is the order of germ layers during embryonic development

Answer 14

Ectoderm (outer)
Mesoderm (middle)
Endoderm (inner)

Question 15

What is the coelem

Answer 15

The body cavity; space between the endoderm and mesoderm

Question 16

What are the 3 basic kinds of body plans

Answer 16

Acoelomates
Pseudocoelomates
Coelomates

Question 17

What are acoelomates

Answer 17

no body cavity

Question 18

What are pseudocoelomates

Answer 18

body cavity between mesoderm and endoderm

Question 19

What are coelomates

Answer 19

Body cavity entirely within the mesoderm

Question 20

What is an Open Circulatory system

Answer 20

blood passes from vessels into sinuses, mixes with body fluids, and reenters the vessels

Question 21

What is a closed circulatory system

Answer 21

blood moves continuously through vessels that are separated from body fluids

Question 22

What is the Blastula

Answer 22

Mitotic cell divisions of the egg form a hollow ball of cells: the blastula

Question 23

What is the Blastopore

Answer 23

The blastula indents to form a 2 layer thick ball with an opening to the outside

Question 24

What is the archenteron

Answer 24

formed from the blastula, it is a primitive digestive tract

Question 25

What are Protostomes

Answer 25

They develop the mouth first from or near the blastopore

-anus develops either from blastopore or another region of embryo

Question 26

What are Deuterostomes

Answer 26

develop the anus first form the blastopore

-mouth develops later from another region of the embryo

Question 27

Cleavage pattern of embryological features

Answer 27

Protostomes= spiral cleavage

Deuterostomes=radial cleavage

Question 28

Development fate of cells in bilaterians

Answer 28

Protostomes: determinate development
Deuterostomes: indeterminate development

Question 29

Origination of Coelom in Bilaterians

Answer 29

Protostomes= Forms simply and directly from the mesoderm

deuterostomes=forms indirectly from the archenteron

Question 30

Which (protostome or deuterostomes) are more evolutionary recent?

Answer 30

Deuterostomes; evolved from protostomes

Question 31

What are the 2 advantage of segmentation

Answer 31

1. ) allows redundant organ system in adults such as occurs in the annelids
2. ) allows for more efficient and flexible movement because each segment can move independently