Shells are the exoskeletons of clams, snails and oysters. Hope that helps
Answer:
On a biological level, the main difference is that bacteria and free-living cells can live inside or outside a body, while viruses are a non-living collection of molocules that need a host to survive.
Explanation:
Answer: The primary motor cortex for control of voluntary muscles is found in the precentral gyrus of the frontal lobes.
Explanations:
The primary motor cortex is one of the important brain areas involved in motor function. It is found in the precentral gyrus of frontal lobes. It control voluntary muscles and generate impulses needed for movement execution.
Voluntary muscles are muscles that we can control consciously or we can control them at will and we can choose when we want to use them. They are also refers to as skeletal muscles and are attached to bones. The are majorly use for locomotion.
Answer:
b. The surfaces of the membrane are nonpermeable.
Explanation:
This helps the cell membrane to protect the cell.
