In a surface wave such as a water wave,

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

We all have different forms of genes from our parent(s).what are these different forms called? a.alleles b.characters c.dna d.resources

When animals eat, the food is stored and digested in the stomach or a similar structure. but when a unicellular organism like this paramecium eats, the food is stored in which organelle