Q. No.In the genetic code dictionary, how many codons are used to code for all the 20 essential amino acids:
1.
20
2.
64
3.
61
4.
60
What does "lac" refer to in what we call the lac operon:
1. Lactose
2. Lactase
3. Lac insect
4. The number 1,00,000
During transcription, the DNA site at which RNA polymerase binds is called:
| 1. | Promoter | 2. | Regulator |
| 3. | Receptor | 4. | Enhancer |
Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as a 'start' or 'stop' codon:
1. UCG – Start
2. UUU – Stop
3. UGU – Leucine
4. UAC – Tyrosine
In Negative operon:
1. Inducer binds with repressor
2. Co-repressor does not bind with repressor
3. Corepressor binds with inducer
4. CAMP has a negative effect on the lac operon
Due to the discovery of which of the following in 1980, the evolution was termed as RNA world?
| 1. | m-RNA, t-RNA- rRNA synthesize proteins |
| 2. | In some viruses, RNA is the genetic material |
| 3. | RNA has enzymatic property |
| 4. | RNA is not found in all cells |
E. Coli about to replicate was placed in a medium containing radioactive thymidine for five minutes. Then, it was made to replicate in a normal medium. Which of the following observation shall be correct?
| 1. | Both strands of DNA will be radioactive |
| 2. | One strand is radioactive |
| 3. | Each strand is half radioactive |
| 4. | None is radioactive |
Chargaff's rule states that in an organism:
| 1. | The amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C). |
| 2. | The amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C). |
| 3. | The amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G). |
| 4. | Amounts of all bases are equal. |
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