A tall pea plant (Tt) is crossbred with another tall pea plant (Tt). The following Punnett square shows the separated alleles for two pea plants.

Punnett square showing female parent across the top with a phenotype of tall and a genotype of Tt and a male parent across the side with a phenotype of tall and a genotype of Tt. Inside the top left box 1 is written, inside the top right box 2 is written, inside the bottom left box 3 is written, inside the bottom right box 4 is written.

Which of the following shows the correct match of the box numbers and the genotype of the offspring?

A. 1 = Tt; 2 = tt; 3 = Tt; 4 = tt
B. 1 = Tt; 2 = Tt; 3 = Tt; 4 = Tt
C. 1 = TT; 2 = Tt; 3 = Tt; 4 = tt
D. 1 = TT; 2 = TT; 3 = Tt; 4 = tt
(THE ANSWER IS NOT B)

Ryan rears sheep for their wool. recently the quantity of wool that ryan gets has diminished. this is because the new sheep are not that wooly. ryan should add which nutrient to their feed so that the sheep becomes more wooly? a.cornb.ironc.cottonseedd. vitamin a

In a classic experiment using pea shape, mendel conducted two separate genetic crosses. in the first cross the parent plants were “true breeding” for pea shape; one had round peas ( r )and the other had wrinkled (r). the first cross produced a filial 1 generation of all round peas. in the second cross, mendel bred plants from the filial 1 generation. this cross produced different results. out of approximately 1000 plants, about 75% were round and 25% were wrinkled.

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.