1, 3-4, 7, 9(a), 11,
1-26, 28-29, 3132, 34
27, 30, 33
Option D: 30
Some numbers as
L earning Objectives
1. Compile your own glossary from the KEY WORDS
displayed in bold type in the learning objectives below.
The genetic blueprint
Nucleic acid structure (pages 128-130, 132-135,
also see 150)
2. Name some examples of nucleic acids and describe
their role in biological systems.
3. Describe the components of a (mono)nucleotide: a 5C
sugar (ribose or deoxyribose), a nitrogenous base
(purine or pyrimidine), and a phosphate. Identify the
bases that form nucleotides.
4. Understand the role of condensation reactions in
joining the components of nucleotides and in the
formation of di- and polynucleotides (nucleic acids).
5. Outline the structure of nucleosomes, including
reference to the role of histone proteins in packaging
of the DNA in the nucleus.
6. Understand that DNA contains repetitive sequences
and that only a small proportion constitutes genes.
Appreciate the role of repetitive sequences in DNA
technologies such as DNA profiling.
7. Describe the Watson-Crick double-helix model of DNA
structure and the base pairing rule. Explain the
importance of complementary base pairing to the
conservation of the base sequence in DNA. Contrast
the structure and function of DNA and RNA.
8. In more detail than #7 above, describe the structure of
DNA including the antiparallel strands, the 3’–5’
linkages, and the role of the hydrogen bonding
between purines and pyrimidines.
DNA replication (pages 136-137)
9. Describe the semi-conservative replication of DNA,
and interpret experimental evidence for this process.
Explain the role of the following in DNA replication:
(a) DNA polymerase, helicase, DNA ligase.
(b) DNA polymerase III, RNA primase, DNA
polymerase I, Okazaki fragments, and
10. Understand that DNA replication proceeds only in the
5’ → 3’ direction and explain the significance of this. Explain the term: replication fork, and explain its
significance in eukaryotic chromosomes.
11. Demonstrate an understanding of the base-pairing rule
for creating a complementary strand from a template
12. Appreciate the role of polymerase chain reaction (PCR)
as an artificially induced form of DNA replication, used
as a tool in molecular biology (see the topic Aspects of
Biotechnology for coverage of this technique).
The genetic code (page 131)
13. Explain the main features of the genetic code,
including reference to the following:
(a) The 4-letter alphabet and the 3-letter triplet code
(codon) of base sequences.
(b) The non-overlapping, linear nature of the code.
(c) The universal nature of the code.
(d) The degeneracy of the code.
(e) The way in which the code is always read from a
start point to a finish point in a 3’ → 5’ direction.
(f) Specific punctuation codons and their significance.
Gene expression (pages 138-143)
14. Outline the basis by which information is transferred
from DNA to protein. Distinguish clearly between allele
and gene. Explain what is meant by gene expression
and define its two distinct stages: transcription and
translation. Note that gene expression is sometimes
used to refer just to transcription.
15. Recall the structure and role of messenger RNA
(mRNA). In simple terms, describe the process of
transcription, identifying the role of RNA polymerase.
16. In more detail than in #15 above, describe the process
of transcription. Demonstrate an understanding of the
direction of transcription (5’ → 3’ direction).
17. Distinguish between the coding (sense) strand,