What best describes the cell membrane? A. It is a single layer of lipids
B. It is an impenetrable barrier
C. It is strong, rigid, and durable
D. It is a lipid bi-layer

How does the study of genetic disorders such as pku biologists understand normal alleles?

Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between twoblack-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately howmany of the 20 offspring would have brown hair?

Study the picture of the ocean. which is the best example of an organism’s niche shown in the picture? a. the environment contains several of the same species of coral. b. the shallow area of the ocean meets the needs of the coral and the fish. c. the ocean has fish and coral that live in the same area. d. the coral take in food from the water and provide shelter for the fish.