St Peter the Apostle High School
BIOLOGY DEPARTMENT
DNA STRCUTURE AND REPLICATION HOMEWORK
NAME: ________________
TEACHER COMMENT:
PUPIL COMMENT:
PARENT COMMENT:
HOMEWORK 1
1. How many adenine molecules are present in
a DNA molecule of 4000 bases, if 20% of the
base molecules are cytosine?
A. 400
B. 600
C. 800
D. 1200
2. If ten percent of the bases in a molecule of
DNA are adenine, what is the ratio of adenine
to guanine in the same molecule?
A. 1:1
B. 1:2
C. 1:3
D. 1:4
3. Which of the following statements about
DNA replication is correct?
A. Polymerase adds nucleotides to the
3’ end of a DNA strand
B. Polymerase adds nucleotides to the
5’ end of a DNA strand
C. Ligase adds nucleotides to the 3’ end of a
DNA strand
D. Ligase adds nucleotides to the 5’ end of a
DNA strand
4. Which of the following diagrams correctly shows the structure of DNA?
5. The diagram below shows a nucleotide from a molecule of DNA.
a) Name the parts K, L and M
K = ____________________
L = ____________________
M = ____________________
b) The percentage of bases in one strand of a DNA double helix is as
follows:
C=22%
T=
40%
i) What is the percentage of bases A and G together in the same strand?
____________________ %
ii) What is the percentage of bases of bases A and G together in the
complementary strand of DNA?
____________________ %
6. a) Complete the diagram below by adding letters to represent
complementary base pairs then label deoxyribose sugars with an S and
phosphates with a P.
b)
7.
HOMEWORK 2
Essay Question:
Give an account of DNA under the following headings:
(i) the structure of DNA;
(5)
(ii) the replication of DNA.
(5)