AQA · A-Level · Biology
Course version: 7402 · Version from Sept 2016
The concept of the genome as the complete set of genes in a cell and of…
Full specification wording
DNA and protein synthesis: The concept of the genome as the complete set of genes in a cell and of the proteome as the full range of proteins that a cell is able to produce.
The genome is the complete set of genes in a cell.
Checked against the AQA 7402 specification (opens in a new tab) on .
- Point 1 of 7
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
The genome is the complete set of genes in a cell. It belongs to a specific cell or organism, not a species or population. Note that the genome is not simply 'all the DNA', as eukaryotic DNA includes significant non-coding regions outside of genes, such as multiple repeats. The proteome is the full range of proteins that a cell is able to produce. The two are linked but distinct. Every body cell of an organism carries the same genome, yet a liver cell and a muscle cell contain different proteins because different genes are expressed. In eukaryotes, the proteome is larger than the gene count because pre-mRNA from one gene can be alternatively spliced, and proteins can be modified after translation.
What earns the marks
- The genome is defined as the complete set of genes in a cell or organism.
- The proteome is defined as the full range of proteins that a cell is able to produce.
- The genome codes for the proteins of the proteome.
- Different cells in the same organism have different proteomes due to differential gene expression.
Common mistakes and how to put them right
Equating the genome to 'all the DNA in a cell'.
Put it right: Eukaryotic DNA includes non-coding regions outside of genes.
Defining the genome as all the genes in a species.
Put it right: The genome refers to a cell or organism.
Giving the proteome as 'the number of proteins'.
Put it right: It is the full range of proteins a cell can produce.
Claiming liver and muscle cells differ because they have different genomes.
Put it right: They differ in their proteomes due to gene expression.
Exam tips
- Anchor both definitions to 'a cell' or 'an organism' to ensure accuracy.
- If asked why the proteome is larger than the number of genes, explain the alternative splicing of pre-mRNA.
Try the lesson
The start of the DNA and protein synthesis: The concept of the genome as the complete set of genes in a cell and of the proteome as the full range of proteins that a cell is able to produce. lesson, made from checked teaching notes for this specification point.
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What is meant by the genome of a cell?
Listen
The genome is the complete set of genes in a cell. It belongs to a specific cell or organism, not a species or population. Note that the genome is not simply 'all the DNA', as eukaryotic DNA includes significant non-coding regions outside of genes, such as multiple repeats. The proteome is the full range of proteins that a cell is able to produce. The two are linked but distinct. Every body cell of an organism carries the same genome, yet a liver cell and a muscle cell contain different proteins because different genes are expressed. In eukaryotes, the proteome is larger than the gene count because pre-mRNA from one gene can be alternatively spliced, and proteins can be modified after translation. A strong answer earns marks for these points. The genome is defined as the complete set of genes in a cell or organism. The proteome is defined as the full range of proteins that a cell is able to produce. The genome codes for the proteins of the proteome. Different cells in the same organism have different proteomes due to differential gene expression. A common slip: Equating the genome to 'all the DNA in a cell'. Instead, eukaryotic DNA includes non-coding regions outside of genes. Exam tip: Anchor both definitions to 'a cell' or 'an organism' to ensure accuracy.
Key words
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genome
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proteome
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alternative splicing
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See every definition
- genome
- The complete set of genes in a cell or organism, not simply all the DNA, as eukaryotic DNA includes non-coding regions outside of genes.
- proteome
- The full range of proteins that a cell is able to produce, which is larger than the gene count in eukaryotes.
- alternative splicing
- The process by which pre-mRNA from one gene can be spliced in different ways, making the proteome larger than the gene count in eukaryotes.
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