Bacterial cell membranes do not have cholesterol. The principal function of the cell membrane is to regulate the substances that enter the cell and the substances that move out of the cell. Cholesterol is a fat like substance that is found in all human cells; it is an important constituent of the cell membrane and it enhances the fluidity of the cell. Bacterial have plasma membrane but the membrane do not contain cholesterol.
Answer:
C
Explanation:
Mutualism is a relationship between two parties where <em>both parties </em>are benefited.
This means the answer would be C- "Ants feed on aphid wastes and protect the aphids from predators."
The <em>ants</em> benefit from a feeding source.
The <em>aphids</em> benefit from predator defense.
<u>In answer C, both parties are benefited, so this is mutualism!</u>
1. A mudslide wipes out the side of a thriving hill: This is negative as many trees and other organisms will get destroyed.
2. A volcano erupts, covering the nearby land with lava: This is negative as molten and extremely hot lava can cause serious damage to its surroundings.
3. A forest is rapidly growing new plant life: This is positive because new plants are being grown.
4. Humans remove wolves from a national park to protect surrounding homes: This is positive for humans because humans will be safe but it is negative for the eco system as removal of wolves can upset the eco system cycle.
5. A dam is built in the middle of a river ecosystem to supply water to a nearby town: This is positive for humans as a new water resource is being developed for humans but negative for aquatic organisms as the dam can hamper their ecosystem and can cause pollution in water.