Question

What are linked genes? How can a pair of linked genus be identified?

Answer 1

A gene is a sequence of nucleotides in DNA or RNA that encloses the synthesis of a gene product either RNA or protein and linked genes are genes that are likely to be inherited together because they are physically close to one another on the same chromosomes.

Complete Answer:
- Genes that are located on the same chromosomes are called linked genes. Alleles for the genes tend to segregate together during meiosis, unless they are separated by crossing-over. Crossing-over occurs when two homologous chromosomes exchange genetic material during meiosis.
- If the genes are fat apart on a chromosome, or a different chromosome, the recombination frequency is In this case, heritance of alleles at the two loci are independent. If the recombination frequency is less than We can say the two loci are linked.

Linked genes can be identified easily on crossing male and female, If the number of progenies is more like parents this means the genes are linked. Whereas if the number of recombines or non-parental types produced are more in number then genes are not linked. The frequency of crossing-over between genes is used to construct linkage maps that show the locations of genes on chromosomes.

In humans this is the X or the Y chromosomes. And so some of the more familiar sex-linked traits are hemophilia, red-green color blindness, conyenital night blindness, some high blood pressure genes, Duchenne muscular dystrophy and also fragile X syndrome.

Note: We always designate linked genes each side in the same order, it is always ab/ba. The rule that genes are always written in the same order permits geneticists to use a shorter rotation in which the wild-type allele is written with a plus sign alone.
The only way to identify linked genes was through mathematical analysis of the relative frequencies of the genes in family groups.