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Biology-Related Homework Help Genetics and Developmental Biology Topic started by: sam01 on Feb 12, 2015



Title: The genes for miniature wings
Post by: sam01 on Feb 12, 2015
The genes for miniature wings (m) and garnet eyes (g) are approximately 8 map units apart on chromosome 1 in Drosophila.

Phenotypically wild-type females (m + g / mg +) were mated to miniature-winged males with garnet eyes.

Which of the following phenotypic classes reflect offspring that were generated as a result of a crossover event?
A.wild type
B.miniature wings, garnet eyes
C.miniature wings
D.garnet eyes

If 800 offspring were produced from the cross, in what numbers would you expect the following phenotypes?

__wild type : __ miniature wings : __ garnet eyes : __ miniature wings, garnet eyes
Enter your answer as the number of flies of each phenotype separated by a colon (example: 100:300:100:300).


Title: Re: The genes for miniature wings
Post by: raneensayegh on Feb 17, 2015
part 1:
Part A
Which of the following phenotypic classes reflect offspring that were generated as a result of a crossover event?
Select all that apply.

these two:
   miniature wings, garnet eyes
   wild type

part 2:
Part B
If 800 offspring were produced from the cross, in what numbers would you expect the following phenotypes?

__wild type : __ miniature wings : __ garnet eyes : __ miniature wings, garnet eyes
Enter your answer as the number of flies of each phenotype separated by a colon (example: 100:300:100:300).
32:368:368:32

Correct
If the genes for miniature wings (m) and garnet eyes (g) are linked with 8 map units between them, then the two recombinant classes must add up to 8% of the total (4% each) and the two parental classes must add up to 92% of the total (46% each).

As a result, the following distribution would be expected:

wild type: 4% x 800 = 32
miniature wings: 46% x 800 = 368
garnet eyes: 46% x 800 = 368
miniature wings, garnet eyes: 4% x 800 = 368