Which action is unable to produce variation?

Chromosome segregation in anaphase I is consistent with which statement?

In tomatoes, red (R) is dominant to yellow (r), tall (D) is dominant to dwarf (d), and smooth (H) is dominant to hairy (h). How many possible different phenotypes are there in relationship to these three characteristics?

In mice, the allele for colored fur (C) is dominant to the allele for albinism (c). The allele for normal behavior (W) is dominant to that for waltzing movement (w). Give the probable genotypes of the parents if a colored normal crossed with a white waltzer produced 10 colored normal, 8 colored waltzers, 2 white waltzers, and 11 white normal.

In humans, normal skin pigmentation is influenced by a dominant gene (C), which allows pigmentation to develop. All individuals who are homozygous for the recessive allele (c) are unable to produce an enzyme needed for melanin formation and are therefore referred to as albino. Two normal parents produce an albino child. What are the chances that the next child will be an albino?

Pairs of maternal and paternal chromosomes line up between the two spindle poles during _______________.

If a child more strongly resembles one parent’s physical traits than the other parent’s, the explanation could be due to chromosome movements during ________________.

In radishes, long or round are homozygous forms of an incompletely dominant gene, and oval is the phenotype of the heterozygote. If a long radish is crossed with a round radish, which of the following phenotypic ratios of the F2 generation is correct?

Stress-induced depression has been found to be a result of which of the following?

Protein products of which genes “put the brakes” on the cell cycle when DNA is damaged or incompletely copied?