What defines the position and presence of coding and a template strand in the transcription unit ?
(1) Structural gene
(2) Ori
(3) Terminator
(4) Promoter
Which of the following is true for both transcription and DNA replication?
1. Principle of complementarity governs the processes
2. Only of the two strands act as template
3. Only a segment of both strands is involved
4. Adenine base pairs with thymine
The DNA dependent DNA polymerases catalyze:
1. Only in 3'-5' direction
2. Only in 5'-3' direction
3. In both directions
4. In neither directions
Which non-radioactive isotope was used by Meselson and Stahl to label DNA in their experiment?
\(1.\ {}^{35}S\)
\(2.\ {}^{15} N\)
\(3.{}^{32} P\)
\(4.\ N o n e\)
Histones are :
(1) Positively charged and basic proteins
(2) Negatively charged and basic proteins
(3) Positively charged and acidic proteins
(4) Found in bacteria
Which of the following is not a feature of the double helix model of DNA ?
(1) The two chains have anti-parallel polarity
(2) A purine always comes opposite to a pyrimidine
(3) The pitch of the DNA is 3.4 nm
(4) The two chains are coiled in a left handed fashion
To form a nucleoside, a nitrogenous base is linked to a pentose sugar:
(1) Through a P-Glycosidic linkage at carbon atom number 1
(2) Through a P-Glycosidic linkage at carbon atom number 5
(3) Through a N-Glycosidic linkage at carbon atom number 1
(4) Through a N-Glycosidic linkage at carbon atom number 5
Which of the following codons has a dual role in the genetic code?
(1) AUG
(2) GUG
(3) CUG
(4) UUG
The inducer of lac operon is :
1. Beta galactosidase
2. Galactose
3. Lactose
4. Glucose
DNA chemically is less reactive and structurally more stable than RNA. Therefore,
1. DNA has evolved from the RNA
2. RNA can directly code for proteins
3. DNA is the better genetic material than RNA
4. The protein synthesizing machinery has evolved around RNA