The inducer of lac operon is :

1. Beta galactosidase

2. Galactose

3. Lactose

4. Glucose

regulatory domains of most activators interact with

1. the transcription factor complex

2. RNA polymerase

3. repressors

4. the DNA binding domain

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

A synthetic mRNA of repeating sequence 5'-CACACACACACACACAC... is used for a cell-free protein synthesizing system like the one used used by Nirenberg. If we assume that protein synthesis can begin without the need for an initiator codon, what product or products would you expect to occur after protein synthesis?

1. one protein, consisting of a single amino acid

2. three proteins, each consisting of a different, single amino acid

3. two proteins, each with an alternating sequence of two different amino acids

4. one protein, with an alternating sequence of two different amino acids

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

Genetic information in a DNA molecule is coded in the:

1. Sequence of nucleotides

2. Base pairings 

3. Proportion of each base present

4. The turning pattern of the helix