Question of 20
If a cytosine replaces a guanine in a strand of DNA, this is known as what type of mutation?

Substitution mutation

Deletion mutation

Insertion mutation

Corruption mutation

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Explain the cellular functions that occur when antibiotics attack a bacteria cell. a. antibiotics target the cell wall, cell membrane, and the processes of protein and nucleic acids production in bacteria to rupture the cell. b. antibiotics create dormant resistant endospores to preserve the genetic material and rupture the cell. c. antibiotics target the cell wall and form a bridge-like connection to form conjugation. d. antibiotics use binary fission to grow twice its size, replications its dna, and split into two cells.

What is the most abundant vertebrate on earth?