Question

Describe the relationship between linkage groups and chromosomes.

Answer 1

When genes are located on different chromosomes they segregate independently, but when they are located on the same chromosome, there is no segregation and they go together to the same gamete. This process is called gene binding.

Step-by-step explanation:

When genes are located on different chromosomes they segregate independently, but when they are located on the same chromosome, there is no segregation and they go together to the same gamete. This process is called gene binding.

In the process of independent segregation, an AaBb individual produces 4 types of gametes, at a rate of 25% each. When a case of gene binding occurs, the individual AaBb produces only AB and ab gametes, at a rate of 50% each.

The link between the genes may be incomplete, because during meiosis prophase 1, when homologous chromosomes are paired, exchanges of parts occur between sister chromatids in a process called crossing-over or permutation. These exchanges result in the formation of recombinant gametes, which are chromosomes with new allele combinations.

If there was no recombination in these genes, the proportion of gametes formed by a double heterozygote would be 50% AB and 50% ab. When recombination occurs, a small proportion of recombinants are observed in the progeny.

Answer 2

The relationship between linkage groups and chromosomes is that the fist ones are all of the genes on a single chromosome.

Step-by-step explanation:

Linkage groups are a group of genes present at different loci on the same chromosome. So a chromosome constitutes one linkage group that is inherited as a group during cell division. The haploid number of chromosomes shows the maximum number of linkage groups.

A linkage is the tendency that genes have to remain together during inheritance in the original combination.