Molecular Basis of Inheritance — Page 16 | NEET Biology

Q151

DNA fragments are:

A Negatively charged

B Neutral

C Either positively or negatively charged depending on their size

D Positively charged

Correct Answer

Option A

Solution

(a) DNA fragments are negatively charged because of presence of phosphate group.

Q152

A nucleotide is formed of

A purine, pyrimidine and phosphate

B purine, sugar and phosphate

C nitrogen base, sugar and phosphate

D pyrimidine, sugar and phosphate

Correct Answer

Option C

Solution

(c) Nucleotide is a unit of DNA, which is formed of nitrogenous bases (purines & Pyrimidines), sugar (Pentose) & phosphate.

Q153

Nucleosome core is made of histone proteins

A

H 1, H 2 A, H 2 B

and

H 3

B

H_1, H_2 A, H_2 B, H_4

C

H 1, H 2 A, H 2 B, H 3

and

H 4

D

H_2A, H_2B, H_3

and

H_4

Correct Answer

Option D

Solution

(d) The four histone proteins constituting the core of nucleosome are $H 2 A, H 2 B, H 3, H 4$ .

Q154

The transforming principle of Pneumococcus as found out by Avery, MacLeod and McCarty was

A mRNA

B DNA

C protein

D polysaccharide

Correct Answer

Option B

Solution

(b) The transforming chemical discovered by Griffith in his experiments with Pneumococcus, was confirmed as DNA by Avery, McLeod and McCarty.

Q155

Who proved that DNA is basic genetic material?

A Griffith

B Watson

C Boveri and Sutton

D Hershey and Chase

Correct Answer

Option D

Solution

(d) Hershey and Chase (1952) worked on Escherichia coli and conclusively proved that DNA is the genetic material.

Q156

The final proof for DNA as the genetic material came from the experiments of:

A Hershey and Chase

B Avery, Mcleod and McCarty

C Hargobind Khorana

D Griffith

Correct Answer

Option A

Solution

(a) Hershey and Chase proved that DNA is the genetic material. They used bacteriophage for their experiment.

Q157

A DNA with unequal nitrogen bases would most probably be

A single stranded

B double stranded

C triple stranded

D four stranded

Correct Answer

Option A

Solution

(a) A single strand of DNA would not possess complementary base pairs. Hence nitrogenous bases are unequal in number.

Q158

Reverse transcriptase enzyme

A RNA dependent RNA polymerase

B DNA dependent RNA polymerase

C DNA dependent DNA polymerase

D RNA dependent DNA polymerase

Correct Answer

Option D

Solution

(d) H.

Temin and D.

Baltimore (1970) discovered that tumor viruses contain RNA as genetic material and replicate by synthesizing complementary DNA.

This process is called reverse transcription and it is carried by an RNA dependent DNA polymerase called as reverse transcriptase.

Q159

The eukaryotic genome differs from the prokaryotic genome because

A genes in the former case are organized into operons

B the DNA is complexed with histones in eukaryotes

C repetitive sequences are present in eukaryotes

D the DNA is circular and double stranded in prokaryotes

Correct Answer

Option C

Solution

(c) The eukaryotic genome differs from prokaryotic genome because repetitive sequences are present in eukaryotes.

Q160

How many base pairs (bp) are found in the haploid genome of humans?

A

2.9 \times 10^{9}

B

4 \times 10^{8}

C

7 \times 10^{9}

D

3 \times 10^{9}

Correct Answer

Option D

Solution

(d) The number of base pairs (bp) found in the haploid genome of humans is $3 \times 10^{9}$ .