You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium. You have isolated a mutation that causes constitutive melibiase activity, which you designate MelA–. P1 phage mapping experiments using a Tn5 insertion linked to Mel1 show that MelA– is not linked to Mel1. Moreover you find that when an amber suppressor is introduced into a MelA– mutant, normal melibiase regulation is restored. Classify the MelA– mutation on the basis of genetic properties,  make a proposal for the type of regulatory functions affected by the MelA– mutation?

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#Question id: 15842

#Unit 8. Inheritance Biology

In the yeast cross of ade2 met14 his3 x + + +, a total of 120 tetrads are analyzed. The markers ade2, met14, and his3 are abbreviated a, m, and h and the wild type allele of each gene is indicated by +.

      

Given three locus from above, which locus shows the tetratype (T)

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#Question id: 15843

#Unit 8. Inheritance Biology

You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts-1 to ts-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml.           What is the distance between the ts-1 and ts-2 mutations in m.u.?

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#Question id: 15844

#Unit 8. Inheritance Biology

You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts^-1 to ts^-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml.  

If the total size of the phage is 5 x 10⁴ bp and the total genetic map length of the phage is 100 m.u., about how far apart are the mutations in base pairs?

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#Question id: 15845

#Unit 8. Inheritance Biology

You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts-1 to ts-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml. Find out the relative order of sm, ts-1 and ts-2?

TLS Online TPP Program

#Question id: 15846

#Unit 8. Inheritance Biology

You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts-1 to ts-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml. the relative order is sm→ts-2→ts-1, find out the distances you can calculate in m.u.?

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#Question id: 17267

#Unit 8. Inheritance Biology

In humans, albinism (unpigmented skin, hair, and eyes) is due to an enzymatic deficiency, and it is an autosomal recessive trait. Suppose that in a small country of one million people (“Generation 1”), there are 500 aa albinos and 9000 Aa heterozygous carriers. Estimate q, the frequency of allele a, in Generation 1. Show your calculations.