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

A transcription unit does not contain:

1. A promoter

2. The structural gene

3. A terminator

4. An operator

Regulation of lac operon by repressor is referred to as:

1. Inducible regulation

2. Repressible regulation

3. Negative regulation

4. Positive regulation

Fredrick Griffith accidentally discovered transformation when attempting to develop a vaccine for pneumonia. He injected mice with samples from S-strain (virulent) and/or R-strain (nonvirulent) pneumococci bacteria (Sterptococcus pneumoniae). Which of the following results is NOT consistent with Griffith's experiments?

1. injected S-strain; mouse dies. 

2. injected R-strain; mouse lives. 

3. injected heat-killed S-strain; mouse lives. 

4. injected mixture of heat-killed S-strain and live R-strain; mouse lives. 

Which scientists first gave experimental evidence that DNA is the genetic material?

1. Avery, MacLeod , and McCarty who repeated the transformation experiments of Griffith, and chemically characterized the transforming principle.

2. Garrod, who postulated that Alcaptonuria, or black urine disease, was due to a defective enzyme.

3. Beadle and Tatum, who used a mutational and biochemical analysis of the bread mold Neurospora to extablish a direct link between genes and enzymes. 

4. Meselson and Stahl who showed that DNA is replicated semiconservatively.

The function of the rho protein is 

1. to help terminate translation

2. to help RNA polymerase bind to the DNA

3. to help RNA polymerase find a promoter

4. to help terminate transcription

Which of the following is a genetic material?

1. Dideoxyribo nucleic acid

2. Deoxyribo nucleic acid

3. Deoxyribulose nucleic acid

4. Deoxyribosome nucleic acid

Polymerisation of which of the following produces Nucleic acids?

1. Nucleosides

2. Nucleotides

3. DNA and RNA

4. Both A and B

Which of the following is a genetic material in most of the organisms?

1. DNA

2. RNA

3. Both DNA and RNA

4. Nucleic Acid