Differentiation of organs and tissues in a developing organism, is associated with:

(1) developmental mutations

(2) differential expression of genes

(3) lethal mutations

(4) deletion of gens

The Okazaki fragments in DNA chain growth:

(1) result in transcription

(2) polymerize in the 3’-to-5’ direction and forms replication fork

(3) prove semi-conservative nature of DNA replication

(4) polymerize in the 5’-to-3’ direction and explain 3’-to-5’ DNA replication

The two polynucleotide chains in DNA are:

(1) parallel

(2) discontinuous

(3) antiparallel

(4) semiconservative

One gene-one enzyme relationship was established for the first time in:

(1) Neurospora crassa

(2) Salmonella typhimurium

(3) Escherichia coli

(4) Diplococcus pneumoniae

A sequential expression of a set of human genes occurs when a steroid molecule binds to the:

1. transfer RNA

2. messenger RNA

3. DNA sequence

4. ribosome

Which antibiotic inhibits interaction between t-RNA and m-RNA during bacterial protein synthesis?

(1) Erythromycin

(2) Penicillin

(3) Streptomycin

(4) Tetracycline

Amino acid sequence, in protein synthesis is decided by the sequence of

(1) t-RNA

(2) m-RNA

(3) c-DNA

(4) r-RNA

One gene-one enzyme hypothesis was postulated by:

1. R. Franklin

2. Hershey and Chase

3. A. Garrod 

4. Beadle and Tatum

One turn of the helix in a B-form DNA is approximately:

(1) 20 nm

(2) 0.34 nm

(3) 3.4 nm

(4) 2 nm

Antiparallel strands of a DNA molecule means that:

(1) one strand turns anti-clockwise

(2) the phosphate groups of two DNA strands, at their ends, share the same position

(3) the phosphate groups at the start of two DNA strands are in opposite position (pole)

(4) one strand turns clockwise