Final answer:
The relationship between the degree of crossing over and the distance between two genes is direct, meaning the greater the distance, the higher the frequency of recombination. This is the basis for constructing genetic maps and determining genetic distance in centimorgans.
Step-by-step explanation:
The relationship between the degree of crossing over and the distance between two genes is direct: as the distance increases, the frequency of recombination increases. Specifically, when two genes are closer together on a chromosome, they are more likely to be inherited together, which results in fewer recombinant offspring and a lower frequency of recombination. Conversely, if genes are further apart on the chromosome, there is more opportunity for crossing over to occur between them, which leads to a higher frequency of recombination and more recombinant offspring.
Recombination frequency is a crucial measure used by geneticists to construct genetic maps and estimate the genetic distance between genes. The units used are centimorgans (cM), where a recombination frequency of 0.01 corresponds to 1 cM. This allows geneticists to create linear maps of gene locations and calculate their distances, thus predicting how likely genes are to be inherited together.
The most accurate statement regarding the relationship between the degree of crossing over and the distance between two genes is option E: It is direct: as the distance increases, the frequency of recombination increases.