Molecular Basis of Inheritance MCQ

Molecular Basis of Inheritance MCQ/Objective question Chapter 6 Biology Class 12

The genetic material in most of the organism is:

  • a. DNA
  • b. RNA
  • c. Nucleotide
  • d. Nuceoside
Answer
a. DNA
Explanation
In some viruses RNA act as a genetic material.

Which nucleotide is present in RNA but not in a DNA?

  • a. Adenine
  • b. Guanine
  • c. Thymine
  • d. Uracil
Answer
d. Uracil
Explanation
In RNA thymine is replaced by uracil

Which among these is not a pyramidine group based nucleotide?

  • a. Adenine
  • b.Cytosine
  • c. Uracil
  • d. Thymine
Answer
a. Adenine
Explanation
There are two groups of nucelotide bases. Purine include Adenine and guanine, Pyrimidine includes cytosine, uracil and thymine.

A nuclotide base is linked to -OH group of sugar. Which bond is it?

  • a. Molecular Basis of Inheritance MCQAmide linkage
  • b. N-Glycosidic bond
  • c. 3′-5′ phosphodiester bond
  • d. Hydrogen bond
Answer
Explanation

In a double stranded DNA. The amount of bases is always:

  • a. A+T = C+G
  • b. A+C =  T+G
  • c. A/T = C/G
  • d. None
Answer
b. A+C =  T+G
Explanation
A always pairs with t and C always pairs with G so, A+C = T+G

Complementary bases in a DNA are tide with which bond?

  • a. Carbond bond (C-C)
  • b. Hydrogen bond (H-H)
  • c. Amide bond (-CONH)
  • d. None
Answer
b. Hydrogen bond (H-H)

How many hydrogen bonds are there between cytosine and guanine?

  • a. one
  • b. Two
  • c. Three
  • d. Four
Answer
c. Three
Explanation
Adenine binds with thymine by two hydrogen bonds while guanine binds with cytosine using three hydrogen bond.

As per central dogma of  Francis Crick genetic information flows as:

  • a. DNA<RNA<Protein
  • b. RNA<DNA<Protein
  • c. DNA<Protein<RNA
  • d. None
Answer
a. DNA<RNA<Protein

Octamer of which protein wraps DNA to form nucleosome?

  • a. Tubulin
  • b. Myosin
  • c. Histone
  • d. None
Answer
c. Histone
Explanation

Transcriptionally active part of chromatin is:

  • a. Euchromatin
  • b. Heterochromatin
  • c. Both
  • d. None
Answer
a. Euchromatin
Explanation
Some part of chromatin are not dense. It stains light and during transcription form RNA. This is called euchromatin. A denser part of chromatin is heterochromatin. It stains dark and does not take part in transcription.

In Griffith’s experiment of Streptococcus on mice, Extract of dead smooth strain made the rough starin virulent. Which material transferred from the dead smooth starin did that?

  • a. DNA
  • b. RNA
  • c. Protein
  • d. None
Answer
a. DNA
Explanation
Avery, Mcleod and carty used DNAse, RNAse and Proteases to know which caused R starin to become virulent. DNAse inhibited transformation. This showed that DNA from smooth strain transformed rough strain to become virulent.

Which organism is more likely to mutate at a faster rate?

  • a. Bacteria
  • b. DNA virus
  • c. RNA virus
  • d. All have the same chances to mutate
Answer
c. RNA virus
Explanation
RNA are more reactive than DNA, so they are more prone to mutate.

How DNA is the genetic material established by Hershey and chase?

  • a. Using S and R strain of Streptococcus
  • b. Using bacteriophage with
  • c. Both
  • d. None
Answer
Explanation

The formation of extra set of DNA from parentral DNA is:

  • a. Replication
  • b. Transcription
  • c. Translation
  • d. None
Answer
a. Replication
Explanation

Set of enzymes that assist replication is:

  • a. DNAse
  • b. RNAse
  • c. DNA polymerase
  • d. All
Answer
c. DNA polymerase

DNA polymerase runs in which direction?

  • a. 5′ to 3′
  • b. 3′ to 5′
  • c. Both
  • d. None
Answer
a. 5′ to 3′

DNA strand with 3′ to 5′ polarity replicate in samller fragents. The nick formed is sealed by:

  • a. DNAse
  • b. DNA polymerase
  • c. DNA ligase
  • d. Telomerase
Answer
c. DNA ligase

Process of formation of RNA from DNA is called:

  • a. Replication
  • b. Translation
  • c. Transcription
  • d. All
Answer
c. Trancription

Transcription starts at which region of DNA?

  • a. Promoter
  • b. Structural gene
  • c. Terminator
  • d. Anywhere
Answer
b. Structrual gene

Only one strand of DNA undergoes transcription. This strand is know as:

  • a. Coding strand
  • b. Template strand
  • c. None
Answer
b. Template strand

Which among these is not a stage of transcription?

  • a. Initiation
  • b. Elongation
  • c. Termination
  • d. Ligation
Answer
d. Ligation

Coding sequence of RNA is called:

  • a. Exons
  • b. Introns
  • c. Codons
  • d. Sense
Answer
a. Exons

Non-coding sequence that is Intron is removed during maturation of RNA by process:

  • a. Ligation
  • b. Splicing
  • c. Capping
  • d. Tailing
Answer
b. Splicing

Stop codons are:

  • a. UUU, GGG, CCC
  • b. AAA, AAU, AAG
  • c. UAA, UAG, UGA
  • d. None
Answer
c. UAA, UAG, UGA
Explanation
Out of 64 combination three codons donot code for any amino acids. They act as stop codon. They are:

Ocre: UAA

Amber:UAG

Opal: UGA

Start codon for RNA translation is:

  • a. AUG
  • b. ACG
  • c. UAA
  • d. UAG
Answer
a. AUG
Explanation
AUG is alwways presnt in RNA as atarting point for translation. It codes for methionine.

Scickle cell anaemia is a an example of:

  • a. Point mutation
  • b. Frameshift insertion
  • c.Frameshift deletion
  • d. None
Answer
a. Point mutation

See also:

Molecular Basis of Inheritance MCQ/Objective question Chapter 6 Biology Class 12

Ref: ch6

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