81. In the genetic code dictionary how many codons are used to code for all the 20 essential amino-acids?
82. What would happen if in a gene encoding polypeptide of 50 aminoacids 25th codon (UAU) is mutated to UAA ?
A. A Polypeptide of 24 aminoacids will be formed
B. Two polypeptides of 24 and 25 aminoacids will be formed
C. A polypeptide of 49 aminoacids will be formed
D. A polypeptide of 25 aminoacids will be formed
Answer : Option A
83. Which one of the following triplet codes, is correctly matched with its specificity for an aminoacid in protein synthesis or as ‘start’ or ‘stop’ codon ?
84. What does “Lac” refer to in what we call the lac operon ?
85. The following ratio is generally constant for a given species
86. During transcription if the nucleotide sequence of the DNA strand that is being coded is ATACG then the nucleotide sequence in the m RNA would be
87. Which one of the following makes use of RNA template to synthesize DNA
A. DNA polymerase
B. RNA polymerase
C. Reverse transcriptase
D. DNA dependant RNA polymerase
Answer : Option C
88. In oogenesis which cells are produced at the first division of primary oocyte in maturation phase ?
A. Secondary oocyte
B. First polar body
C. Secondary polar body
D. (a) and (b) both
Answer : Option D
89. Which stage of cell at the time of ovulation.
A. Secondary oocyte
B. First polar body
C. Secondary polar body
D. Primary oocyte
Answer : Option B
90. When sperm penetrate secondary oocyte during its unequal meioticdivision, how many polar body (bodies) is are produced ?