Bar is a gene often used in recombination study. Which of the following is true for the Bar gene?
  • a) It is normally present in two copies
  • b) Three copies of bar are called ultra bar
  • c) Heterozygous bar females have a less severe effect than homozygous bar female
  • d) Homozygous bar are of common occurrence
Consider that recombination occurs in 2 strand stage of meiosis. If a Drosophila is heterozygous for the bar locus what will be the result of recombination?
  • a) The recombination will make them homozygous
  • b) It will produce ultra bar phenotype
  • c) It will be heterozygous
  • d) No exchange
Chiasmatype theory states recombination occurs before chiasma formation. State whether it is true or false.
  • a) True
  • b) False
How many rounds of replication in BrdU will be needed to visualize Harlequin chromosome?
  • a) Single
  • b) Two
  • c) Three
  • d) Four
If two genes are unlinked the recombination frequency will be?
  • a) 25%
  • b) 50%
  • c) 75%
  • d) 100%
Is two crossovers occur between same two strands, this will result in__________
  • a) All recombinant strands
  • b) Three recombinant strands with different loci exchanged
  • c) Exchange of middle portion between two strands
  • d) Exchange of ends
Double cross over involving ________ strands result inrecombinant strands.
  • a) 1
  • b) 2
  • c) 3
  • d) 4
If a recombination event of three points crossing produces 6 DCO,SCO andNCO. What will be the percentage cross over between the terminal genes.
  • a) 10%
  • b) 20.8%
  • c) 14.8%
  • d) 30.8%
If single cross over frequency between two genes r and q and q and s in 3 point mapping is 0.6 and 0.2 respectively. What will be the expected double cross over frequency?
  • a) 0.012
  • b) 0.010
  • c) 0.022
  • d) 0.024
In an experiment you calculate the expected DCO frequency to be 0.but in reality you observe that only 0.recombination frequency. What is the phenomenon resulting in this?
  • a) Coincidence
  • b) Interference
  • c) Penitence
  • d) Expressivity
Which of the following will result in parental phenotype?
  • a) DCO in between two genes considering four strands
  • b) Even number of DCO between two genes
  • c) Odd number of DCO between two genes
  • d) Single cross over at 4 strand stage between two genes
What will be the nature of curve with map distances plotted in X axis and percentage recombination in Y axis?
  • a) Parallel to X axis
  • b) Increasing in a straight line
  • c) Parabolic
  • d) Exponential
0 h : 0 m : 1 s