A corn plant known to be heterozygous at three loci is testcrossed. The progeny phenotypes and numbers are as follows:+ + + 455a b c 470+ b c 35a + + 33+ + c 37a b + 35+ b + 460a + c 475Total 2,000Give the gene arrangement, linkage relationships, and map distances.

The progeny phenotypes and numbers are as follows:

+ + + 455 parental

a b c 470 parental

+ b c 35 recombinant

a + + 33 recombinant

+ + c 37 recombinant

a b + 35 recombinant

+ b + 460 parental

a + c 475 parental

Total 2,000

+ + + 455 parental

a b c 470 parental

+ b + 460 parental

a + c 475 parental

It is two point testcross

So the parental ++ (455+460); ac (470+475)++/ac

Gene order is ++/ac

+ b c 35 recombinant

a + + 33 recombinant

+ + c 37 recombinant

a b + 35 recombinant

sum of recombinants140

Frequency of recombintion= recombinants/total x100

Map distances between a-c = (140/2000) x 100 = 7 mu

a7 mu c

Explanation:

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".