TLS Online TPP Program

#Question id: 5654


Two human disorders, Prader-Willi syndrome and Angelman syndrome, occur when a small deletion in a specific region of chromosome 15 is contributed by either the father or mother, respectively. Why does this small deletion not behave as a recessive allele for either syndrome, that is, why is its loss not made up for by the good copy of the region on chromosome 15 contributed by the other parent?

#Unit 5. Developmental Biology
  1. This portion of chromosome 15 is invariably mutated, so the other parent contributes recessive alleles that are thus homozygous and perturb development.

  2. The copy of chromosome 15 from the other parent has genes in the region of the deletion that are imprinted, and thus inactive; in the absence of any active copies of these genes, development cannot proceed normally.

  3. The genes in this portion of chromosome 15 are special in that they are required in two copies for normal development, and so the loss of one set does not allow normal development.

  4. Chromosomes with deletions do not go through mitosis correctly, so cell divisions in the embryo result in cells with abnormal numbers of chromosomes, and these cells do not contribute properly to the development of the organism.

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TLS Online TPP Program

#Question id: 12998

#Unit 1. Molecules and their Interaction Relevant to Biology

Match with appropriate bonding pattern

TLS Online TPP Program

#Question id: 12999

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline and glycine both disturb the symmetry of α-helix which of the following are true regarding to these two amino acids
a) proline changes the orientation of hetropolymeric α-helix hence proline can be placed only as 1st amino acid residue near to C-terminus 
b) proline changes the orientation of polymeric α-helix hence proline can be placed only as 1st amino acid residue near to N-terminus
c) glycine disrupts the heteropolymeric α-helix by changing the helicity.
d) homopolymer of proline and glycine can form stable helix. 

TLS Online TPP Program

#Question id: 13000

#Unit 1. Molecules and their Interaction Relevant to Biology

Identify the correct statement regarding the structure


TLS Online TPP Program

#Question id: 13001

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is incorrect 
a) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and linear H bonding pattern.
b) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and having distorted H bonding pattern.
c) parallel β sheets are relatively less stable and mostly found in core of protein.
d) parallel β sheets are relatively more stable and mostly found in core of protein.

TLS Online TPP Program

#Question id: 13002

#Unit 3. Fundamental Processes

Where in a eukaryotic cell do you think you would find each of the following proteins residing when it is actively performing its function. Be as specific as you can in terms of subcellular location.
Match the following with the correct subcellular location;

 

I) Polymerases

 

 

a) In the cytoplasm

 

II) Ribosomal proteins

 

 

b) Inside the plasma membrane.

 

III) DNA ligase

 

 

c) In the mitochondrial matrix

 

IV) protein that allows ions to pass in and out of the cell

 

 

d) In the nucleus of cells

 

V) Activator protein

 

 

e) Inside the nuclear membrane

 

VI) an enzyme in the Krebs/TCA cycle

 

 

 

VII) a protein that forms a channel through which mRNAs can be exported into the cytoplasm

 

 

 

TLS Online TPP Program

#Question id: 13003

#Unit 8. Inheritance Biology

If 200 meiocytes with AaBb and   80 meiocytes  undergoes to single crossing over between  gene A and B. What will be the chance of crossing over and what is the recombination frequency of the gametes?