Consider two imaginary genes, a “finger number gene” and a “hand size gene”, in
ID: 66043 • Letter: C
Question
Consider two imaginary genes, a “finger number gene” and a “hand size gene”, in an imaginary population of aliens. Since we’re imagining things, let’s also imagine that the aliens have diploid genomes and life cycles just like human beings. Each gene has two possible alleles. For the finger number gene, "N" is the dominant allele for having 4 fingers on each hand, and "n" is the recessive allele for having 5 fingers on each hand. For the hand size gene, "H" is the dominant allele for having small hands, and "h" is the recessive allele for having large hands. Neither gene is on a sex chromosome.
You observe a "parental" generation cross: NNHH x nnhh. The offspring of that cross are called the "F1" generation. F1 individuals are then crossed with the genotype nnhh (i.e., a "testcross").
Suppose you count 1000 offspring of the testcross and find the following results:
470 offspring with four fingers on small hands
480 offspring with five fingers on large hands
27 offspring with four fingers on large hands
23 offspring with five fingers on small hands
From these data, you should conclude that:
Question 26 options:
The two genes are on the same chromosome, 50 map units apart
The two genes are on the same chromosome, 5 map units apart
The two genes are on the same chromosome, 23 map units apart
The two genes are on the same chromosome, 95 map units apart
The two genes are on separate chromosomes
The two genes are on the same chromosome, 50 map units apart
The two genes are on the same chromosome, 5 map units apart
The two genes are on the same chromosome, 23 map units apart
The two genes are on the same chromosome, 95 map units apart
The two genes are on separate chromosomes
Explanation / Answer
Answer:
B. The two genes are on the same chromosome, 5 map units apart
In the rtesult, four fingers on small hands & five fingers on large hands (parental combinations) are more when compare to four fingers on large hands & five fingers on small hands (recombinant combinations). Hence we can conclude that they are present on the same chromosome and very closely arranged.