Module 2.1: Animal Architecture

Question 1

What are the 5 levels / grades of Organization in Organ complexity?

Answer 1

1. Protoplasmic grade
2. Cellular grade
3. Cell-Tissue grade
4. Tissue-Organ grade
5. Organ-system grade

Question 2

Differentiate between Radial and Spherical symmetry.

Answer 2

Radial: any organism that can be divided into two similar halves by more than two planes
Spherical: Any plane (from any direction) that passes through the center will produce two mirrored images.

Question 3

Describe the three planes of symmetry.

Answer 3

Frontal plane: separates the dorsal and ventral portions
Sagittal plane: separates right side and left side
Transverse plane: separates the anterior and posterior portions

Question 4

3 Functions of Body Cavities

Answer 4

1. Internal space / Housing
2. Cushion
3. Locomotion

Question 5

Define the term “Diploblastic”

Answer 5

A body that originates from only TWO germ layers (ectoderm and endoderm.) Usually sponges and jellyfishes.

Question 6

Determine how many body cavities are formed via acoelomate, pseudocoelomate, and coelomate plan.

Answer 6

Acoelomate: 1 (gut)
Pseudocoelomate: 2 (gut & blastocoel)
Coelomate: 2 (gut & blastocoel)

Question 7

What are the two methods of a coelomate plan?

Answer 7

1. Schizocoelous (mesoderm forms from blastula lining)
2. Enterocoelous (mesoderm forms from splitting; splitting from gut)

Question 8

Differentiate between spiral and radial cleavage.

Answer 8

Spiral: Blastopore –> mouth, cleavage is mosaic, body is either acoelomate, pseudocoelomate, or coelomate (schizocoelous); PROTOSTOMES
Radial: Blastopore –> anus, cleavage is regulative, body is coelomate, DEUTEROSTOMES (enterocoelous)