chApTer-6 : MOLecULAr BASIS OF INherITANce
Multiple choice Questions
- DNA consists of two complementary polynucleotide
chains. If the sequence of nucleotides in one of the chains
is AGCTTCGA, then the nucleotide sequence in the other
chain shall be
(a) TAGCATAT (b) TCGAAGCT
(c) GATCCTAG (d) GCTAAGCT
- Anticodon is a base triplet present on
(a) mRNA, complementary to base sequence on rRNA
(b) mRNA, complementary to base sequence on tRNA
(c) tRNA, complementary to base sequence on rRNA
(d) tRNA, complementary to base sequence on mRNA.
- DNA and RNA are different molecules as
(a) DNA has cytosine and RNA has guanine
(b) DNA has uracil and RNA has thymine
(c) DNA is a micromolecule and RNA is a macromolecule
(d) DNA has thymine and RNA has uracil.
- The concept of central dogma is
(a) protein → RNA
(b) protein → RNA
(c) RNA → → protein
(d) → RNA → protein
- 61 codons code for 20 different types of amino acids. This
property of genetic code is called
(a) colinearity (b) polarity
(c) degeneracy (d) nonambiguity.
- In a double stranded DNA molecule, the percentage
of cytosine is 18. What would be the percentage of
adenine?
(a) 32% (b) 64%
(c) 36% (d) 18%
- In lac operon, the genes a, i, y and z code respectively
for
(a) repressor protein, permease, b-galactosidase,
transacetylase
(b) transacetylase, permease, b-galactosidase, repressor
protein
(c) permease, transacetylase, repressor protein,
b-galactosidase
(d) transacetylase, repressor protein, permease,
b-galactosidase.
- The result of which of the following reaction experiments
carried out by Avery et. al. on Streptococcus pneumoniae
proved conclusively that DNA is the genetic material?
(a) Live ‘R’ strain + DNA from ‘S’ strain + RNase
(b) Live ‘R’ strain + DNA from ‘S’ strain + DNase
(c) Live ‘R’ strain + Denatured DNA of ‘S’ strain +
protease
(d) Heat killed ‘R’ strain + DNA from ‘S’ strain +
DNase
- Which of the following statements regarding ‘human
genome’ is incorrect?
(a) Human genome consists of 3 × 10^9 bp and about
20,000-25,000 genes.
(b) The average gene size is 3000 bp and the gene for
Duchenne Muscular Dystrophy is the largest known
human gene.
(c) Chromosome 1 contains maximum (2968) number
of genes and the Y-chromosome has the least (231)
number of genes.
(d) Repeated (or repetitive) sequences are not present in
human genome.
- Arrange the various steps of DNA fingerprinting process in
the correct order.
(i) Separation of DNA fragments by electrophoresis.
(ii) Digestion of DNA by restriction endonucleases.
(iii) Hybridisation using labelled VNTR probes.
(iv) Isolation of DNA.
(v) Detection of hybridised DNA fragments by auto
radiography.
(vi) Transferring the separated DNA fragments to
nitrocellulose membrane.
(a) (iv) → (ii) → (i) → (vi) → (iii) → (v)
(b) (iv) → (i) → (ii) → (iii) → (vi) → (v)
(c) (ii) → (i) → (iv) → (vi) → (iii) → (v)
(d) (iii) → (v) → (iv) → (ii) → (i) → (vi)
True or False
- Repetitive DNA is the DNA having multiple copies of
identical sequences of nitrogen bases.
- The process of copying genetic information from one strand
of the DNA into RNA is termed as translation.
- DNA has evolved from RNA with chemical modifications
that made it more stable.
- Polycistronic mRNA is more common in prokaryotes
whereas monocistronic mRNA is common in eukaryotes.
- Induction is turning off of an operon which normally remains
switched on.
- Single stranded RNA is the genetic material in reovirus.
- Lagging strand does not require DNA ligase.
- DNA replication in eukaryotes is semiconservative,
semidiscontinuous and bidirectional.
- An auxotroph is a mutant which is not able to prepare its
own metabolites from the raw materials obtained from
outside.
