Question

When a cluster of genes show linkage behaviour, they
A. Do not show chromosome map
B. Induce cell division
C. Do not show independent assortment
D. Show recombination during meiosis

Answer 1

As the DNA sequence containing the genes is passed around as a unit during meiosis, genes that are located on the same chromosome and that appear to be inherited together are considered related genes unless they are separated by crossing over.

Complete Answer:
- Genetic Linkage is the two or more than two forms of a given gene. These linkages are together and are closely located on a chromosome. Further these linkages are inherited together during the process of producing gametes such as sperm cells or egg cells in sexually reproducing organisms.
- During the process of reproducing egg cells also called meiosis, the same type of chromosomes pair up together and then exchange their matching sections of DNA. Thus, this leads to finishing up genes on different chromosomes that were originally on the same chromosome.
- This process is called Genetic Recombination. The recombination events of two or more forms of genes are finished if linkage is complete Thus only alleles containing parental combinations are observed in offspring.
- It is the state where two genes located in a fixed position on a chromosome are so close together that their genes can not be separated. The closer they are,Less likely they are separated by crossing over events.
- Clustering is the method in which linkage data sets are interpreted.clustering actually means to a group of things that are similar in nature. The two nearest data points are clustered together and make one single data for further clustering. This process is continued till we get one single data. The linked genes which are clustered show linkage and they do not follow independent assortment .

The correct answer is option C) Do not show independent assortment.

Note: The closer genes are found on a single chromosome, the greater the possibility that they will be inherited as a unit, since the closer the two genes are, the less frequent the crossing between two related genes is (genes with maximum linkage are near enough together on a chromosome that they never recombine and are still inherited as a unit). Genes that show linkage results in more parental types and very less recombinants in the progeny.