- Trans for ma tion was dis cov ered by [CBSE AIPMT 2014]
(a) Meselson and Stahl (b) Her shey and Chase
(c) Grif fith (d) Wat son and Crick
- Grif fith’s ex per i ment proved that
(a)DNA is the ge netic ma te rial
(b)there are two strains of Strep to coc cus pneumoniae
(c)some trans form ing fac tors trans formed rough bac te ria into
smooth bac te ria
(d)RNA is the trans form ing fac tor
- Which of the fol low ing is not rel e vant to the struc ture of
dou ble he li cal DNA.
(a)The he lix makes one com plete spi ral turn ev ery 34Å
(b)The di am e ter of the he lix is 20Å
(c)The dis tance be tween ad ja cent nu cle o tide is 3.4Å
(d)Each strand of he lix has a back bone made up of
al ter nat ing ribose sugar and phos phate
- The re sult of the fol low ing re ac tion/ex per i ment car ried
out by Avery et al. on Strep to coc cus pneumoniae has
proved con clu sively that DNA is the ge netic material
(a) live ‘R’ strain + DNA from ‘S’ strain + DNAse
(b) heat killed ‘R’ strain + DNA from ‘S’ strain + DNAse
(c) live ‘R’ strain + DNA from ‘S’ strain + RNAse
(d) live ‘R’ strain + Denatured DNA of ‘S’ strain + protease
- In Hershey and Chase experiments, radioactive^32 P
was used to culture bacteriophages which resulted in
radioactive [Kerala CEE 2011]
(a) viral DNA
(b) bacterial capsule
(c) viral proteins
(d) protein capsule of bacteriophage
- Which property among those listed below is not a
criteria for a molecule to act as a genetic material?
[Kerala CEE 2014]
(a) Generate its replica
(b) Chemically and structurally stable
(c) Mutate slowly to facilitate evolution
(d) Destroy itself after every cell cycle
- A base pair consists of a purine and pyrimidine
because
(a)the space available between two chains of DNA, i.e. 2 nm
can accommodate only such pair
(b)there is perfect match between hydrogen donor and
acceptor sites on two bases
(c)two polynucleotide chains of DNA are complementary to
each other
(d)All of the above
- Which of the following Chargaff's rule is incorrect?
(a)The DNA molecule has equal A—T and G—C base pairs
(b)Purines (A + G) are always equal to pyrimidines (T+C)
(c)The amount of A is always equal to that of ‘T’ and the
amount of ‘G’ is always equal to that of C.
(d)The base ratio A+T/G+C varies for a given species
9. If double stranded DNA with^15 N undergoes
replication twice in a normal medium, then which of
the following is correct?
(a) Half bacteria contain^15 N in DNA
(b) All four contains^15 N in DNA
(c) None contains^15 N in DNA
(d) 3/4 bacteria^15 N in DNA
10 .......stabilises the chain in the single stranded form to
reduce the energy needed to unwind the DNA helix.
(a) Topoisomerase
(b) Helicase
(c) SSB protein
(d) Gyrase
11 .Identify the incorrect difference from the following
given differences between leading and lagging strand
and select the correct option.
Leading strand Lagging stand
(a) It grows continuously as a
single piece
It is formed initially as short
segments called Okazaki
segments
(b) It needs a single RNA primer
to start its growth
Each segment needs a
separate RNA primer to start
(c) It does not need DNA ligase DNA ligase is needed to join
Okazaki fragments
(d) Direction of growth is 3 ′→ 5 ′ Direction of growth of each
Okazaki fragment is 3 ′→ 5 ′
12 .Histones are a set of positively charged proteins which
are rich in
(a) lysine and asparagine (b) lysine and arginine
(c) valine and glutamine (d) valine and serine
13 .Which of the following is a major difference in
replication in prokaryotes and eukaryotes?
(a)Replication in prokaryotes is conservative while it is
semiconservative in eukaryotes
(b)Prokaryotes do not require small RNA primer for initiation of
replication as in eukaryotes
(c)Prokaryotes have single origin of replication and
eukaryotes have multiple origin of replication
(d)All of the above
14 .Select the correct option [CBSE AIPMT 2014]
Direction of RNA synthesis Direction of reading of the
template DNA strand
(a) 5 ′→ 3 ′ 3 ′→ 5 ′
(b) 3 ′→ 5 ′ 5 ′→ 3 ′
(c) 5 ′→ 3 ′ 5 ′→ 3 ′
(d) 3 ′→ 5 ′ 3 ′→ 5 ′
15 .All cells undergo semiconservative mode of
replication, but the mechanism and enzyme differs in
eukaryotic and prokaryotic cells. Identify the correct
statements regarding replication in prokaryotic cells.
I.DNA ligase joins the RNA primers.
II.DNA polymerase catalyses polymerisation in 5 ′ → ′ 3
direction.
