Question

please give diagram off cross qnd ratio of F1 and F2 progeny.

Understanding concepts of complementation versus F2 cross progeny' information (in this example, anyway)& what you can conclude etc. Q: regarding no.'s of F2 orange:yellow progeny if yı mutation and y3 mutation were located on the same chromosome & 10mu apart (RFs 10%, information provided) & 2000 F2 progeny. (Note: initial parental cross pure breeding yellows strain X pure-breeding yellows strain) u sild tyre y. & уз located on same chromosome: allelic mutations yiA ys 10mu apart: inked U2 yellovs ello w уз

Answer 1

Note that the colours are not for the genes but for that the mutations.

Mutant genes are in red. Wildtypes are in black.

Parent 2 ters YelLow F4 produced 3 Reuombinahan ORANGE ORANGE 91 Ys

All the F1 progeny are orange.

A cross of F1 × F1 is done.

Total of 10% of gametes will be recombinants.

90% gametes will be parentals.

The following shows the combinations and proportions of the zygotes (F2 offspring)

0.9 × 0.9 = 0.81 × 2000 = 1620 Parentals.

0.9 (parent 1 × 0.1 (parent 2) = 0.09 × 2000 = 180 half recombinants

0.1 (parent 1) × 0.9 (parent 2) = 0.09 × 2000 = 180 half recombinants.

0.1 × 0.1 = 0.01 × 2000 = 20 double recombinants

The following pictures show the phenotypes of the respective genotypes.

To get the orange phenotype, the offspring should at least one wildtype allele of each gene.

1620 parentals (04x04) 08D

Orange = 810

Yellow = 810

360 3/ of 2000 1 YELLOW YELLOW 180 ORAN GE 180

lhet 2000 → YELLOW ORANGe 15 Yellow 5

Adding all the orange offspring:

810 + 180 + 15 = 1005

By the adding the yellows we get 995 yellow offspring.

The ratio of orange to yellow is:

1005 : 995

or

201 : 199