Chapter 25: Protostomes

Question 1

Primary characteristics of animals?

Answer 1

Multicellular
Heterotrophs
Store energy as glycogen and fat
Make collagen
Lack Cell wall
Specialized cells and tissues
Motile at some time in their lives
Reproduce sexually and asexually
Mostly Complex development

Question 2

Innovation 1:

Answer 2

Tissues: Group of similarly specialized cells for a particular function
Formation of tissues on the process of development
Diploblastic-> 2 Layers
Triploblastic->3 Layers

Question 3

Endoderm

Answer 3

The innermost layer that forms the lining of the gut and resp. system

Question 4

Ectoderm

Answer 4

The outermost layer that forms the external covering and nervous system

Question 5

Mesoderm

Answer 5

Between other layers, forms the structures between gut and external covering.

Question 6

Innovation 2:

Answer 6

Symmetry
Radial: Body parts arranged around central axis
Bilateral: Mirror image along midline, led to cephalization (development of the head)

Question 7

Innovation 3

Answer 7

Body plans

Question 8

Acoelomate

Answer 8

No Body Cavity

No Separation of gut from body wall

Question 9

Pseudocoelomate

Answer 9

Pseudocoelum: fluid filled or organ-filled space between endoderm and mesoderm

Question 10

Coelomate

Answer 10

True coelum- fluid-filled body cavity entirely lined by peritoneum derived from mesoderm.
Mesenteries surround inner organs

Question 11

Innovation 4:

Answer 11

Development of the body plan

Question 12

Innovation 5:

Answer 12

Segmentation
Arise from the mesoderm
In invertebrates, each segment may include a complete set of important organs and muscles which may help survive damage and locomtion control

In vertebrates, it allows flexibility of movement

Question 13

1. Phylum Porifera: Sponges

Answer 13

Simple body plan
No tissue layer
Asymmetrical
Sessile
Limited integration of cells
Filter feeders