Question

For single crossovers, the frequency of recombination is half the frequency of crossing over because

A)each crossover takes place between only two of the four chromatids of a homologous pair.
B) test cross between a homozygote and heterozygote produces ½ heterozygous and ½ homozygous progeny.
C)the frequency of recombination is always 50%.
D)crossovers occur in about 50% of meioses.
E)each crossover involves all four chromatids but this only occurs in half the meiotic events.

Answer 1

The frequency of recombination in single crossovers is half the frequency of crossing over because each crossover involves all four chromatids, but this only occurs in half of the meiotic events. Crossover is the first source of genetic variation in meiosis, leading to the exchange of genetic material between homologous chromosomes. The frequency of recombination can be calculated based on genetic distance and is usually less than 50% in linked genes.

Step-by-step explanation:

The frequency of recombination in single crossovers is half the frequency of crossing over because each crossover involves all four chromatids, but this only occurs in half of the meiotic events. During meiosis, homologous chromosomes can undergo a crossover, which is the exchange of genetic material between chromatids. This crossover event results in new combinations of maternal and paternal genes, increasing genetic variation. The frequency of recombination can be calculated based on the genetic distance between genes, and it is typically less than 50% in linked genes.