Chapter 33 A - Animal Diversity

Question 1

Animals general characteristics

Answer 1

Heterotrophs
Multicellular
No Cell Walls
Active Movement
Diverse in Form
Diverse in Habitat
Sexual Reproduction
Embryonic Development
Unique Tissues

Question 2

2 types of tissue classification

Answer 2

Parazoa - lack of true tissues

Eumetazoa - true tissues

Question 3

Symmetry

Answer 3

How parts of an animal are arranged around an axis

Question 4

3 types of symmetry

Answer 4

Asymmetry - absence of symmetry, no central axis = primitive
Radial symmetry - a central axis, oral - aboral axis = slice of pie
Bilateral symmetry - divide into a right and left halves down a longitudinal axis

Question 5

Cephalization

Answer 5

The evolution of a head and brain area in the anterior end of animals; thought to be a consequence of bilateral symmetry

Question 6

3 embryonic tissue layers

Answer 6

Ectoderm - gives rise to the outer epithelium of the body (skin, hair, nails) and to the nerve tissue, including the sense organs, brain, and spinal cord
Endoderm - gives rise to the epithelium that lines internal structures and most of the digestive and respiratory tracts
Mesoderm - gives rise to muscle, bone, and other connective tissue, the peritoneum, the circulatory system, and most of the excretory and reproductive systems

Question 7

2 tissue level classifications

Answer 7

Diploblastic - two embryonic tissue layers (ectoderm & endoderm)
Triploblastic - all three layers of tissue, leads to the formation of a body cavity

Question 8

Body cavity (coelom) advantages

Answer 8

Room for organ development (digestive system, reproductive system), allow for the separation and compartmentalization of different biological functions in the body
Greater freedom of movement
Increased body size

Question 9

3 types of body cavities

Answer 9

Acoelomate - no true body cavity, solid mass of mesoderm
Pseudocoelomate - fluid filled cavity, tube within a tube, gut not lined with mesoderm
Coelomate - body cavity lined with mesoderm, mesentary

Question 10

Embryonic stages of development

Answer 10

Morula - solid ball of cells
Blastula - hollow ball of cells
Gastrula - formation of body cavity = blastula with opening at 1 end (blastopore)

Question 11

Fate of blastopore

Answer 11

Protostomes - blastopore becomes mouth

Deuterostomes - blastopore becomes anus

Question 12

2 types of cleavage

Answer 12

Spiral cleavage - dividing cells spiral, outward from axis (protostomes)
Radial cleavage - cells divide parallel to and at right angles to axis

Question 13

Fate of embryonic cells

Answer 13

Determinate - cells fate is determined early on (protostomes)
Indeterminate - fate of cells is determined later on in development (deuterostomes)

Question 14

Segmentation (metamerism) advantages

Answer 14

Compartmentalization - individual segments are complete, damage to one segment is localized
Permits the body for specialized functions such as feeding, locomotion, and reproduction

Question 15

Bilateral symmetry advantages

Answer 15

Cephalization (formation of head and brain)
Regional specialization allows for more efficient concentration of effort in one region rather than having the entire body fulfill that function
Moves in one direction