Autosomal-linkage

Define autosomes

Chromosome pairs 1-22

Define linkage

If 2 or more genes are located on the same chromosome, then they are said to be linked

Define autosomal linkage

If genes have loci on a chromosome that’s not a sex chromosome - more likely to be inherited together

What are evidences for autosomal linkage

• The expected ratio is NOT 9:3:3:1

• Large no. of original parental phenotypes show that there must be linkage

• Recombinants are new combinations of phenotypes that were not seen in the original parental phenotypes - proves linkage wasn’t complete

State the exact event in meiosis that results in recombinants

Crossing over in Prophase 1 leads to recombinants

What equation do you use to work out the ratio?

(No. of recombinants / total offspring) x 100

State how high or low the no. of recombinant are with 2 genes that are closer or far apart

The lower the % of recombinants, the closer the gene loci on the chromosome