Isotopes used in proving semiconservative replication of DNA were:

1. ¹⁴N ¹⁴C            

2. ¹⁴N ¹⁵N            

3. ¹⁴N ³¹P             

4. ¹⁴C ³¹P

Bacterial nucleoid has:

1. One single-stranded DNA            

2. One double-stranded DNA

3. Two single-stranded DNA             

4. Many double-stranded DNAs

Column-I                                        Column-II

I. Operator site                               (A) Binding site for RNA polymerase

II. Promoter site                             (B) Binding site for repressor molecule

III. Structural gene                         (C) Codes for enzyme protein

IV. Regulator gene                          (D) Code for repressor molecules

The correct match is:

1. I - B, II - A, III - C, IV - D         

2. I - B, II - A, III - D, IV - C

3. I - D, II - C, III - A, IV - B         

4. I - B, II - C, III - A, IV - D

In chromosome, DNA is associated with:

A. Negatively charged proteins       B. Positively charged proteins

C. Neutral proteins                        D. NHC protein

1. B, D                

2. A, B, C, D       

3. B, C, D            

4. A, B, C

Heterochromatin:

A. Is more densely packed      B. Is stains dark

C. Is transcriptionally active    D. Is transcriptionally inactive

1. A, C                

2. A, B, C, D        

3. B, C, D            

4. A, B, D

In eukaryotes the gene expression is regulated at:

A. Transcriptional level

B. Processing level

C. Transport of mRNA from nucleus to the cytoplasm

D. Translational level

1. A, C               

2. A, B, C, D                 

3. B, C, D                     

4. A, B, C

In prokaryotes, gene regulation occurs at the level of:

1. Transcription                               

2. Translation

3. Post transcription                         

4. Post translation

A. DNA polymorphism plays important role in evolution and speciation.

B. 99.9% nucleotides bases are exactly same in all people

C. Chromosome 1 has the fewest genes (23) and Y-chromosomes has most genes (2968)

D. BAC and YAC have been used in Human Genome Project.

1. All correct                   

2. All incorrect

3. A, B, D are correct       

4. B, C, D are correct

Go through the following diagram of Nucleosome (structural unit of chromatin). Identify its componential parts indicated by A, B and C:

Following is the schematic structure of transcription unit having some important components indicated by A, B, C, D and E. In which of four option the components are identified correctly: