Question

In Drosophila, three recessive genes (A, B, and C) are linked on chromosome 3. A homozygous recessive fly is crossed with a wild-type fly. The F1 flies show the following distribution of phenotypes: a b c 146 a + c 33 + b c 468 a b + 71 + b + 17 a + + 479 + + c 61 + + + 154 (a) What were the genotypes of the two parents in this cross? (2 marks) (b) What is the order of genes A, B, and C? (2 marks) (c) What is the map distance between A and B, and B and C loci? (3 marks)

Name: in drosophila three recessive genes a b and c are linked on chromosome 3 a homozygous recessive fly is crossed with a wild type fly the f1 flies show the following distribution of phenotypes 23299
Uploaded: 2022-04-08T12:32:57-08:00
Duration: 1 min 52 s
Channel: Shaiju T
Description: in drosophila three recessive genes a b and c are linked on chromosome 3 a homozygous recessive fly is crossed with a wild type fly the f1 flies show the following distribution of phenotypes 23299

          In Drosophila, three recessive genes (A, B, and C) are linked on
chromosome 3. A homozygous recessive fly is crossed with a
wild-type fly.
The F1 flies show the following distribution of phenotypes:
a b c 146 a + c 33 + b c 468 a b + 71 + b + 17 a + + 479 + + c
61 + + + 154
(a) What were the genotypes of the two parents in this cross? (2
marks)
(b) What is the order of genes A, B, and C? (2 marks)
(c) What is the map distance between A and B, and B and C loci?
(3 marks)

Added by Stanley H.

Biology for AP Courses

Julianne Zedalis, John Eggebrecht

Instant Answer

Solved by Expert Shaiju T

04/08/2022

Step 1

The wild-type fly would have the genotype ++ ++ ++, where the "+" represents the dominant allele. Show more…

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In Drosophila, three recessive genes (A, B, and C) are linked on chromosome 3. A homozygous recessive fly is crossed with a wild-type fly. The F1 flies show the following distribution of phenotypes: a b c 146 a + c 33 + b c 468 a b + 71 + b + 17 a + + 479 + + c 61 + + + 154 (a) What were the genotypes of the two parents in this cross? (2 marks) (b) What is the order of genes A, B, and C? (2 marks) (c) What is the map distance between A and B, and B and C loci? (3 marks)