Question

Which of the following factors was used by Alfred Sturtevant to measure the distance between the genes and mapped their positions on the chromosome?
(a)Total recombination
(b)Frequency of recombination
(c)Parental gene combination
(d) Non-parental combination

Answer 1

Hint: Gene is a sequence of nucleotides that encodes the gene product which is either RNA or protein. Genes constitute alleles that lead to different variations and acquire mutations in their sequence.

Complete answer:
The factor used by Alfred Sturtevant was the frequency of recombination that hep in measuring the distance between the jeans and mapped their positions on the chromosome. The distance between the two genes is known as the linkage distance which is calculated by dividing the total number of recombinant gametes by the total number of gametes. The measure of the genetic linkage which is used in the creation of a genetic linkage map is known as the recombination frequency with which a single chromosomal crossover can take place between two genes during the process of meiosis. Double crossovers give no recombination and the crossover took place is not determined. The chromosome a short randomly into the gametes during the process of meiosis with which the segregation of alleles of one gene is independent of the alleles of another gene which is the law of independent assortment that holds for genes that are located on different chromosomes.

Additional information:
The presence of the same gene combination that was present in the parents is known as the parental gene combination which takes place when the two genes are present in close association on the same chromosome. the maternal and paternal genetic material recombine during the cross-over in the cell division which leads to the non-parental gene combination. Some progeny receive one parental chromosome after cross over with a dominant allele for one trait that is linked to a recessive allele for a second trait that is true for the other parental chromosome. recombination frequency tends to underestimate the distance between the two linked genes because the genes are located far apart and can cross over between them for a double which increases the chance of crossover.

So, the correct answer is 'Frequency of recombination'.

Note: Humans are 99% identical at their genetic level and the genes can disappear or can break as the species evolve. In the animal kingdom the most rapidly evolving genes are present in the sperms. Octopuses can edit their genes.