Answer Happy

1. Which molecules within a nucleotide form the backbone
of the DNA ladder? (a) Deoxyribose and a phosphate
group
(b) Deoxyribose, a phosphate group, and a nitrogenous
base
(c) Ribose and a phosphate group
(d) A nitrogenous base
2. Scientists have discovered a molecule that inhibits
DNA ligase in replication. They have applied this to a
bacterial cell culture, what impact might this have on the
cells?
(a) Nucleotides cannot be added to template strands.
Hence, DNA replication would not occur at all and cells
cannot reproduce.
(b) Okazaki fragments on the lagging strand cannot forms
bonds with each other to form one continuous strand. Hence,
replication is only completed on the leading
strand.
(c) Mismatch repairs do not occur under the absence of
DNA ligase. Hence, the genome has an increased risk of
mutations and genomic errors.
(d) This would have no impact at all.
5. Which of the following molecules are required to
initiate DNA replication?
i. DNA polymerase
ii. RNA polymerase
iii. RNA primers
iv. Helicase
v. Single-strand binding proteins
vi. Topoisomerase I
vii. Topoisomerase II
viii. Topoisomerase III
(a) i, ii, iv, v, vi (b) i, iii, iv, v,
vi
(c) i, iii, iv, v, vii (d) i, ii, iv, v,
viii