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please help with these 3 questions. thank you! Name: A cross between individuals with genotypes AaBb...

please help with these 3 questions. thank you!
Name: A cross between individuals with genotypes AaBb x aabh produces the following offspring. Genotype Number of offspring A
Name: A series of two-point test-crosses where carried out among eight loci (a,b,c,d,ef.g and h), producing the following rec
Name: A cross between individuals with genotypes AaBb x aabh produces the following offspring. Genotype Number of offspring AaBb Aabb aaBb aabb a. Do the evidence suggest that the a and b loci are linked? Explain your answer. b. What is the map distance between a and b? (Show your work.) c. Are the A and B loci in coupling or repulsion in the heterozygous parent? 4. You perform a testcross between two plants. Plant one is heterozygous for both flower color and pollen shape and has purple flowers and long pollen (BbRr). Plant two is homozygous recessive and has blue flowers and round pollen (brr). The outcome of the cross is as follows: 123 purple flowers, long pollen 21 purple flowers, round pollen 13 blue flowers, long pollen 98 blue flowers, round pollen. a. What is the map distance between the gene for flower color and pollen shape? b. Are the genes for flower color and pollen shape in coupling or repulsion in the heterozygous parent?
Name: A series of two-point test-crosses where carried out among eight loci (a,b,c,d,ef.g and h), producing the following recombination frequencies. adeb c&d 50 de 50 c& 22 ca 11 ca 50 de 50 der 50 50 50 a de 50 a&d so e4 a&f 50 a & adh 2 bac 50 b&d 7 b&e 50 b&f b&g 50 b&h 50 de 50 250 & 6 f&g 15 feb 50 B& 50 How many linkage groups are there in this problem? b. What are the genes in each linkage group? Draw a map of each linkage group including the gene names and the distance between the loci. You can draw this on a separate piece of paper - or here if you printed the homework, take a picture and submit on Moodle. Is there any evidence for any of the loci that double crossovers took place in the two- point crosses? If your answer is yes, describe the evidence.
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Answer #1

Answer:

3).

a).

The cross is Dihybrid test cross. According to Mendel experiments, Dihybrid test cross ratio is 1:1:1:1 when the two genes are assorted independently. But the number of each genotype would not fit in the ratio. Hence, the two genes are linked.

b).

Hint: Always recombinant progeny are small numbered in linkage problems.

Recombination frequency (RF)= (number of recombinants / Total number of progeny) 100

RF= (9+12/100) 100

RF = 21%

RF (%) = Distance between the genes (map units)

Distance between a and b = 21 m.u.

c).

Heterozygote would be Ab/aB. This indicates that the A and B loci in repulsion.

4).

a).

The cross is Dihybrid test cross. According to Mendel experiments, Dihybrid test cross ratio is 1:1:1:1 when the two genes are assorted independently. But the number of each genotype would not fit in the ratio. Hence, the two genes are linked.

b).

Hint: Always recombinant progeny are small numbered in linkage problems.

Recombination frequency (RF)= (number of recombinants / Total number of progeny) 100

RF= (21+13/255) 100

RF = 13.33%

RF (%) = Distance between the genes (map units)

Distance between a and b = 13.33 m.u.

c).

Purple = B; blue = b

Long = R; Round = r

Heterozygote would be purple, long / blue, round = BR/br. This indicates that the B and R loci in coupling.

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