In a certain plant, yellow leaves are dominant () and red leaves are recessive (). A plant with genotype Yy and a plant with YY are crossed, if they have four offspring, how many would you predict would have red leaves? (Hint: Draw a Punnett square to help you determine the answer.) O AO OB. 3 O c. 2 2. O D. 1 apx ans is 0

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.

Label the steps for protein synthesis in order, beginning with the first steponce the protein is made, the gene for a particular trait is expressedmrna joins the ribosome, and the anticodons from trna join mrna to form a chain ofamino acidsrna polymerase unzips dna and free rna nucleotides join dna to form mrnav a chain of amino acids is formed from peptide bonds, creating a proteinmrna is transported from the nucleus of the cell to the ribosomes of the cell.

Recombinant dna is the merging of dna from unrelated organisms to create new genetic varieties is assembled in the lab from mononucleotides was part of the green revolution of the 1960s is pollination of one plant by another of the same species is cross-pollination of one plant by a different species