The following are the characteristics of Cnidaria:
1. The organisms have specialized stinging cells known as cnidocytes.
2. Two types of body plans exist, that is, polyp and medusa.
3. The phenomenon of alternation of generation is observed.
The following are the characteristics of Porifera:
1. The organisms lack symmetry.
2. The adult forms are sessile.
3. The organisms obtain food by filtering water.
Involuntary as the muscle is a reflex
Answer:
permeability
Explanation:
dictionary definition: the state/quality of a material or membrane that causes it to allow liquids or gases to pass through it
in biology we use this term to describe the cell membrane, it is "semi-permeable" because it allows certain gasses and molecules to pass through
Answer:
C. Water
Explanation:
The cells in our bodies are full of water. The excellent ability of water to dissolve so many substances allows our cells to use valuable nutrients, minerals, and chemicals in biological processes. Water's "stickiness" (from surface tension) plays a part in our body's ability to transport these materials all through ourselves.
