Answer: Natural selection occurs when one allele (or combination of alleles of different genes) makes an organism more or less fit, that is, able to survive and reproduce in a given environment. If an allele reduces fitness, its frequency will tend to drop from one generation to the next.
Explanation:
Answer: True
Explanation:
There is something called Skin flora. This refers to a group of microorganisms that reside on the skin. Staphlococcous aureus and Staphlococcous epidermidis are common examples. The Skin flora protects the skin from pathogenic organisms.
It plays an important role in digestion by ensuring that food goes down the esophagus (foodpipe) and not the trachia (windpipe)........