Energy carried by waves

How are gene and protein sequences used to classify organisms?

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.

Atest cross can be used to -predict the phenotypes of a monohybrid cross -predict an unknown genotype of a purebred dominant plant -cross-breed dominant and recessive plants -give probabilities that a trait will appear