Chp 23 Invertebrates

Question 0

Animals with Symmetrical Tissues

Answer 0

If it can be bisected along at least one plane such that the resulting halves are mirror images of one another. Any symmetrical animal has an upper, or Dorsal, surface and a lower, or Ventral, surface.

Question 1

What are Key Features of Animals?

Answer 1

Difficult to devise a concise definition of the term “animal”. No single feature defines animals.
-Multicellular ; Lack a cell wall; Obtain their energy by consuming other organisms; Typically reproduce sexually. Motile; Able to respond rapidly to external stimuli as a result of the activity of nerve cells, muscle tissue or both.

Question 2

Radial Symmetry

Answer 2

Any plane through a central axis divides the object into roughly equal halves

Question 3

Bilateral symmetry

Answer 3

Can be divided into roughly mirror-image halves only along one particular plane through the central axis.