An estimated % of adults 51 years and older lose the ability to absorb vitamin b12 due to atrophic gastritis.

Leila has dimples because she received a gene copy from her father that coded for dimples. this means that dimples are an example of a trait that is

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.

The lineage of pea plants produced round seeds for four generations. the plants that fertilized these pea plants also produced round seeds. however, in the fifth generation, the plant produced to two plants with wrinkled seeds. can that be possible?