3. • In DNA, adenine (A) goes with thymine (T) and
guanine (G) goes with cytosine (C). A, T, C, and
G are all nitrogen bases. If A and T or C and G
are not paired up together it will create a
mutation and the DNA will not replicate.
• Purines- Adenine, Guanine
• Pyrimidines- Cytosine, Thymine
5. • DNA is split by DNA helicase. As DNA
splits, free nucleotides bind to the exposed
bases of the non-coding strand. This process is
helped by RNA polymerase.
• Strand one is the leading strand and strand
two is the lagging strand.
11. • The primary role of DNA polymerase is to
accurately and efficiently replicate the
genome in order to maintain the genetic
information.
• DNA polymerase adds nucleotides
continuously on Strand one.
20. 3’
5’
DNA ligase stitches
together the Okazaki
fragments together.
phosphate
Sugar
Thymine
Adenine
Guanine
Okazaki
Fragments
Cytosine
DNA helicase
3’
Okazaki
Fragments
DNA polymerase
5’
Telomerase is an enzyme that
adds telomerase repeat
sequences to the 3’ end of
DNA strands.
21. • Okazaki fragments are formed because DNA
polymerase which acts as the synthesizer of
DNA can only work at one strand at a time.
The fragments are short, newly synthesized
DNA fragments that are formed by lagging
template strand during DNA replication.
• The fragments are “stitched together by the
enzyme ligase.
22. • DNA needs to replicate. When cells divide, the
new cells produced must have a full set of
genes in order to function correctly. Genes are
made of DNA so it is necessary to replicate the
DNA before the cells divide. Cells divide for
reproduction, growth and repair. DNA needs a
complete set of genes for it to function
properly.