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#Question id: 15657


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 next construct a MelA– MelB– double mutant, which gives the following behavior:
 
Which of your two models is consistent with this new data?
a) the MelA- MelB- double mutant is identical to the MelB- mutant
b) MelA- is epistatic to MelB-
c) MelB- is epistatic to MelA-
d) the MelA- MelB- double mutant is identical to the MelA- mutant
Which of the following is the correct prediction about the double mutants?

#SCPH06 I Botany
  1. A and C
  2. B and D
  3.  C and D
  4. A and B
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TLS Online TPP Program

#Question id: 4743

#SCPH01 Biochemistry

Ectrodactyly is an autosomal dominant trait that causes missing middle fingers (lobster claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by x-ray. Which of the following terms applies to this family?

TLS Online TPP Program

#Question id: 4743

#SCPH06 I Botany

Ectrodactyly is an autosomal dominant trait that causes missing middle fingers (lobster claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by x-ray. Which of the following terms applies to this family?

TLS Online TPP Program

#Question id: 4743

#SCPH12 I Genetics

Ectrodactyly is an autosomal dominant trait that causes missing middle fingers (lobster claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by x-ray. Which of the following terms applies to this family?

TLS Online TPP Program

#Question id: 4743

#SCPH28 | Zoology

Ectrodactyly is an autosomal dominant trait that causes missing middle fingers (lobster claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by x-ray. Which of the following terms applies to this family?

TLS Online TPP Program

#Question id: 4744

#SCPH01 Biochemistry

Assume that long ear lobes in humans are an autosomal dominant trait that exhibits 50% penetrance. A person who is heterozygous for long ear lobes mates with a person who is homozygous for normal ear lobes. What is the probability that their first child will have long ear lobes.

TLS Online TPP Program

#Question id: 4744

#SCPH12 I Genetics

Assume that long ear lobes in humans are an autosomal dominant trait that exhibits 50% penetrance. A person who is heterozygous for long ear lobes mates with a person who is homozygous for normal ear lobes. What is the probability that their first child will have long ear lobes.