Levels of Organization of Living Things

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.

In meiosis ii during anaphase ii which structures separated homologous chromosomes or sister chromatids

Read the article and use the information to answer the following questions. active transport in active transport, molecules are moved across the cell membrane with the of neurons electrical impulses proteins. inhibitors 3 of 3 vity