Working genes
(15 hours)
Transmission of inherited traits from parent(s) to offspring is via the DNA in sex cells. This requires the ability of DNA to self replicate. The way in which the DNA is expressed in each
individual cell, between cells in different tissues and organs and thus the organism as a whole, is via the proteins produced in each cell. This involves transcription of the DNA code and
translation within the cytoplasm. Proteins formed may be structural or may influence the cell metabolism through controlling metabolic pathways as enzymes or hormones. A range of
different mutations (chromosomal, point, transcription and translational) may disrupt the normal functioning of the cell and/or organism. An understanding of DNA structure and gene
action has resulted in biotechnologies that have, and have to potential to, bring about rapid changes to a large number of different organisms. Application of these technologies is subject to
ethical concerns.
Key Concepts:
1. Cells are the functioning units of all living things
4. A variety of mechanisms results in continual change at all levels of the natural world.
5. There are processes which maintain dynamic equilibrium at all organisational levels.
6. There are mechanisms by which characteristics of individuals in one generation are passed on to the next generation.
UNIT ORGANISATION
Main Focus
DNA structure
DNA replication
Structure and function of
the gene
Mutations
Gene technology
Key
Ideas
2
8, 23
22
Suggested Expansion of the Main Focus
Understand the double helix structure of DNA, nucleosome
formation and the chromosome. DNA exists in the nucleus
and some organelles of the eukaryotic cell. The
chromosome of prokaryotes and eukaryotes differ.
Understand that complimentary chains are built up from
the exposed chains of unzipped DNA under enzyme action
from free nucleotides in the nucleus. Unzipping of DNA is
prevented by heat shock proteins.
Develop insights into the structure of the gene, and how it
determines traits through protein synthesis. Each protein is
formed as a result of a code (the gene) on the DNA through
transcription and translation.
10
Gain an appreciation of the ways in which mutations occur
through alterations in chromosomes, genes, transcription or
translation. Each type of mutation could result in changes
in the individual, the population or the species.
18
Understand the difference between cross-breeding and
genetic recombination in producing desired traits in an
organism. Examine applications of genetic recombination
and the production of transgenic organisms, and the current
and possible applications of these technologies to the
human species.
Possible Student Activities and Learning
Experiences
Construction of a DNA molecule.
Experimental extraction of DNA and
nucleotide composition.
Use the model of the DNA molecule to
demonstrate replication.
Construct a model of the process of protein
formation.
Solve problems involving the code, codon and
anticodon.
Predict the effects on amino acid sequencing in
a protein as a result of a variety of different
types of point mutations.
Explain how somatic mutations could result in
senescence.
Write a newspaper report outlining the
techniques and current status of genetic
recombination as applied to either GM food or
the human species. Relate this to future
possibilities and the ethical application of
scientific knowledge.
Skills
Objectives
Text
Reference
6
UB, IB
Ch. 21.1
Ch. 21.5
UB
Ch. 21.2
UB
Ch. 21.3
UB
Ch. 21.4
UB, IB,
EBI
Ch. 24.3