Answer: option D.
Phenotype
Explanation:
Theory of natural selection shows that different organism survive, adapt and reproduce in their environment due to their different phenotypic variation. The phenotypic variation exist among individual organisms and it is heritable which is transfer from one generation to another.
Phenotype are traits or physical characteristics or observable characteristics of organism e.g organisms appearance, behavior e.t.c.
They are variables that cannot be changed or are purposefully not changed in an experiment.
Most of the mutations have no effects whatsoever on the organisms but some can be dangerous. There are two types of mutations that cause harm to the organism's ability to survive:teratogen muations are the mutations that form inside the uterus when the fetus is still developing and can even kill it or cause severe malformations that lead to death in the early life. Carcinogen mutations are the ones that lead to the formation of neoplasms(masses of cells that divide uncontrollably, basicly cancer).
Flagella and cilia have the exact same structures and functions, and the names merely indicate how many are present on a given cell. When found singly or in a pair, these cell protrusions are called flagella<span>.</span>
