Molecular Basis of Inheritance

NEET Biology · 262 questions · Page 24 of 27 · Click an option or "Show Solution" to reveal answer

Q231

Which of the following is not required for any of the techniques of DNA fingerprinting available at present?

A Polymerase chain reaction

B Zinc finger analysis

C Restriction enzymes

D DNA-DNA hybridization

Correct Answer

Option B

Solution

(b) Zinc-finger analysis is used for protein analysis, not DNA fingerprinting.

Q232

Expressed Sequence Tags (ESTs) refers to:

A Genes expressed as RNA

B Polypeptide expression

C DNA polymorphism

D Novel DNA sequences

Correct Answer

Option A

Solution

(a) ESTs are short DNA sequences generated from mRNA — they represent expressed genes.

Q233

The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?

A super-coiling in nucleosomes

B DNase digestion

C through elimination of repetitive DNA

D deletion of non-essential genes.

Correct Answer

Option A

Solution

(a) DNA is packaged by super-coiling around nucleosomes (histones) to fit in the nucleus.

Q234

T.O. Diener discovered a:

A free infectious DNA

B infectious protein

C bacteriophage

D free infectious RNA

Correct Answer

Option D

Solution

(d) Diener discovered viroids — free infectious circular RNA molecules (1971).

Q235

Which one of the following does not follow the central dogma of molecular biology?

A Pea

B Mucor

C Chlamydomonas

D HIV

Correct Answer

Option D

Solution

(d) HIV uses reverse transcription (RNA → DNA), violating the classical central dogma.

Q236

Infectious proteins are present in:

A Gemini viruses

B Prions

C Viroids

D Satellite viruses

Correct Answer

Option B

Solution

(b) Prions are infectious proteins without nucleic acid (cause scrapie, BSE, CJD).

Q237

The unequivocal proof of DNA as the genetic material came from the studies on a

A bacterium

B fungus

C viroid

D bacterial virus

Correct Answer

Option D

Solution

(d) Hershey and Chase used bacteriophage to prove DNA (not protein) is the genetic material.

Q238

Transformation was discovered by

A Meselson and Stahl

B Hershey and Chase

C Griffith

D Watson and Crick

Correct Answer

Option C

Solution

Q239

If the distance between two consecutive base pairs is 0.34 nm and total base pairs = 6.6x10^9 bp, the length of DNA is approximately

A 2.5 meters

B 2.2 meters

C 2.7 meters

D 2.0 meters

Correct Answer

Option B

Solution

(b) 0.34 nm x 6.6x10^9 = 2.244 m ≈ 2.2 m.

Q240

If a completely radioactive double stranded DNA molecule undergoes two rounds of replication in a non-radioactive medium, what will be the radioactive status of the four resulting molecules?

A Half the number contain no radioactivity

B All four still contain radioactivity

C Three out of four contain radioactivity

D Radioactivity is lost from all four

Correct Answer

Option A

Solution

(a) After 2 rounds, 2 of 4 molecules have one radioactive strand (semi-conservative).

Ready for a full NEET mock test? Timed · full syllabus · instant results

Take a Mock Test →