What kind of model is a globe and what are its limits

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.

Select all that apply genes are specific nucleotide sequences occur in numbers that are the same as the number of chromosomes are located in a specific place on a chromosome determine the traits of an organism are units of rna

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.