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just answer c 6. (10 points, optional). A fruit fly of genotype at/a. bt/b (pare

ID: 150958 • Letter: J

Question

just answer c

6. (10 points, optional). A fruit fly of genotype at/a. bt/b (parent 1) is crossed to another fruit fly of genotype a/a b/b (parent 2). The progeny of this cross were: Genotype Number of individuals a/a.b'/b 13 a) What gametes were produced by parent 1 and in what proportions? (4 points) b) Do these proportions demonstrate independent assortment of the two genes? Why? (2 points) c) Draw a diagram of the arrangement of the genes on the chromosomes in parents 1 and parent 2 using the appropriate symbols. If they are linked, label the distance between them. (4 points)

Explanation / Answer

Arrangement of chromosomes in parent 1:

a+_____ b+

a_______b

Arrangement of chromosomes in parent 2:

a________b

a_________b

They are linked, now we will find out the distance between them.

Total number of individuals – (38+37+12+13) = 90

A single crossing over between b and a produces the a+    b and a     b+ which have members 12 an 13 respectively for a total of 25 (12+13).

Therefore, frequency of crossing over between b and a is –

(25/90)*100 = 27.78

So, the distance between a and b is 27.78 m.u.

a___________________27.78_____________________b