TLS Online TPP Program

#Question id: 724


In 1988, Richardson and Richardson observed that certain amino acid residues are statically favored as the amino-terminal caps for the alpha helices in 45 globular proteins. Which of the following statement stand correct with stability of helix?

A. The introduction of a negatively charged side chain at the N-cap, which can neutralize the partial dipole created by the unpaired amide protons, has been shown to increase stability

B. In particular, Gly is often observed at the both C-cap position and N-cap positions

C. In particular, Gly is often observed at the C-cap position only

D. In particular, Gly is often observed at the C-cap position, Asn at the N-cap position, Pro at the Ncap+1 and Asp and Glu at N2 and N3

#Unit 1. Structure and Function of Biomolecules
  1. D only

  2. B Only

  3. C Only

  4. A, B & D

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TLS Online TPP Program

#Question id: 18083

#Unit 8. Inheritance Biology

The interaction of selection and inbreeding in determining the incidence of autosomal recessive diseases. Consider a gene in which recessive mutations occur at a rate of 10-5. Assume a selective disadvantage S of 0.4 in homozygotes for the recessive allele. Would q be expected to rise, fall, or remain unchanged during the first 10 generations after the cessation of inbreeding, Briefly justify your answer. What numerical value would q approach after thousands of generations with no inbreeding?

TLS Online TPP Program

#Question id: 18227

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:
 
Calculate LOD scores for linkage at θ = 0.1 between the disease and SSR62

TLS Online TPP Program

#Question id: 18228

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:
 
Calculate LOD scores for linkage at θ = 0.1 between the disease and SSR93?

TLS Online TPP Program

#Question id: 18229

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:
 
Calculate LOD scores for linkage at θ = 0.1 between SSR62 and SSR93

TLS Online TPP Program

#Question id: 19107

#Unit 8. Inheritance Biology

Assume that mating is random. First, consider an autosomal recessive disease that is usually lethal in childhood, and that has an incidence among newborns of 1/3000.  Perhaps the explanation for the incidence of the disease is heterozygote advantage. How large would this heterozygote advantage have to be (assuming the mutation rate is negligible)? 

TLS Online TPP Program

#Question id: 19111

#Unit 8. Inheritance Biology

If the frequency of PKU among newborns is approximately 1/10,000 (when the parents are unrelated). What is the risk of a child with PKU if the parents are uncle and niece?