How do mutations increase the genetic variation within a species? Why doesn't a mutation ALWAYS affect the organism's phenotype?

What is the purpose behind gene expression and regulation?

(Please answer I’ve been stuck for like a week) (it’s giving me a headache)

Expression of Genes. For a cell to function properly, necessary proteins must be synthesized at the proper time. All cells control or regulate the synthesis of proteins from information encoded in their DNA. The process of turning on a gene to produce RNA and protein is called gene expression.

Explanation:

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

c. would be the answer : )

explanation: