Molecular Basis of Inheritance

NEET Biology · 262 questions · Page 18 of 27 · Click an option or "Show Solution" to reveal answer

Q171

Which of the following forms the basis of DNA Finger printing?

A The relative proportions of purines and pyrimidines in DNA.

B Satellite DNA occurring as highly repeated short DNA segments.

C The relative difference in the DNA occurrence in blood, skin and saliva.

D The relative amount of DNA in the ridges and grooves of the fingerprints.

Correct Answer

Option B

Solution

(b) DNA fingerprinting is a test to identify and evaluate the genetic information-called DNA (deoxyribonucleic acid)-in a person's cells.

DNA fingerprinting is a form of identification based on sequencing specific non-coding portions of DNA that are known to have a high degree of variability from person to person.

These sections are known as Tandem repeats.

The test is used to determine whether a family relationship exists between two people, to identify organisms causing a disease, and to solve crimes.

Q172

The okazaki fragments in DNA chain growth

A polymerize in the 3- to 5 direction and forms replication fork

B prove semi-conservative nature of DNA replication

C polymerize in the 5 to 3 direction and explain 3 to 5 DNA replication

D result in transcription.

Correct Answer

Option C

Solution

Q173

One of the most frequently used techniques in DNA fingerprinting is

A AFLP

B VNTR

C SSCP

D SCAR

Correct Answer

Option B

Solution

(b) The technique of DNA fingerprinting was developed by Dr.

Alec Jeffrey in 1984.

It is a technique generally using repeated sequences (repetitive DNA) in the human genome that produces a pattern of band that is unique for every individuals.

These short nucleotide repeats vary in number from person to person and are called variable number of tandem repeat (VNTR).

VNTR belongs to class of satellite DNA referred to as minisatellite.

Q174

Satellite DNA is important because it :

A shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children.

B does not code for proteins and is same in all members of the population

C codes for enzymes needed for DNA replication

D codes for proteins needed in cell cycle.

Correct Answer

Option A

Solution

(a) Satellite DNA displays high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is inherited from parents to children (offsprings).

Q175

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.

The zinc finger proteins are a super family of proteins involved in numerous activities of plant growth and development.

Q176

Match the following genes of the Lac operon with their respective products:

A (i) (iii) (ii) (iv)

B (iii) (i) (ii) (iv)

C (iii) (i) (iv) (ii)

D (iii) (iv) (i) (ii)

Correct Answer

Option C

Solution

(c) Lac operon consist of one regulatory genes ( $i$ gene) and three structural genes $(z, y$ , and $a$ ). $i$ gene codes for Repressor. $z$ gene codes for Beta-galactosidase. $y$ gene codes for Permease. $a$ gene codes for Transacetylase.

Q177

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) Expressed Sequence Tags (ESTs) are DNA sequences (genes) that are expressed as mRNA for protein synthesis.

These are used in human Genome Project.

Expressed Sequence Tags are small pieces of DNA sequence (usually 200 to 500 nucleotides long) that are generated by sequencing either one or both ends of an expressed gene.

First, each gene (DNA) must be converted, or transcribed, into messenger RNA (mRNA) RNA that serves as a template for protein synthesis.

Q178

At time of organogenesis genes regulate the process at different levels and at different times due to

A promoter

B regulator

C intron

D exon

Correct Answer

Option B

Solution

(b) Introns are non coding intervening sequences on DNA but exons are the coding sequences.

Q179

In which direction m-RNA is synthesised on DNA template?

A 5 to 3

B 3 to 5

C Both

D Any

Correct Answer

Option A

Solution

(a) The enzyme polymerase can synthesize the bases only in $5^{\prime} \to 3^{\prime}$ direction.

Q180

In negative operon system

A co-repressor binds to repressor

B co-repressor binds with repressor

C co-repressor binds with corepressor

D CAMP has negative effect on lac operon

Correct Answer

Option A

Solution

(a) In negative (repressible) operon, the repressor co-repressor complex binds with the operator.

The free repressor cannot bind to the operator.

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

Take a Mock Test →