AQA · GCSE · Biology
Course version: 8461 · Version from Sept 2018
DNA and the genome: The DNA is contained in structures called chromosomes.
Within the nucleus, DNA is packaged into structures called chromosomes.
Checked against the AQA 8461 specification (opens in a new tab) on .
- Point 4 of 9
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Within the nucleus, DNA is packaged into structures called chromosomes. A chromosome is a long molecule of DNA that is associated with proteins, which help to coil and condense the DNA so it can fit inside the nucleus. Humans have 46 chromosomes in a normal body cell, arranged as 23 pairs. Each chromosome carries many genes, and the sequence of bases along the DNA determines the proteins that the cell can make. When you describe this, state that chromosomes are found in the nucleus, that they are made of DNA, and that they carry genetic information.
For example: A human body cell has 23 pairs of chromosomes, with one chromosome of each pair inherited from each parent.
What earns the marks
- DNA is contained in structures called chromosomes.
- Chromosomes are found in the nucleus of eukaryotic cells.
- A chromosome is made of a long DNA molecule associated with proteins.
- Chromosomes carry genetic information in the sequence of bases.
- Human body cells contain 46 chromosomes arranged as 23 pairs.
Common mistakes and how to put them right
Saying that chromosomes are made only of protein.
Put it right by stating that chromosomes contain DNA and associated proteins.
Confusing chromosomes with genes.
Put it right by stating that a chromosome is a structure that carries many genes.
Stating that human gametes have 46 chromosomes.
Put it right by stating that human gametes have 23 chromosomes.
Exam tips
- Use the phrase chromosomes are found in the nucleus when describing location.
- Link chromosomes to DNA and genes in the same answer to show the relationship.
- Quote the human chromosome number as 46 in body cells and 23 in gametes.
Try the lesson
The start of the DNA and the genome: The DNA is contained in structures called chromosomes. lesson, made from checked teaching notes for this specification point.
Have a go first
In which structures is the DNA of a cell contained?
Listen
Within the nucleus, DNA is packaged into structures called chromosomes. A chromosome is a long molecule of DNA that is associated with proteins, which help to coil and condense the DNA so it can fit inside the nucleus. Humans have 46 chromosomes in a normal body cell, arranged as 23 pairs. Each chromosome carries many genes, and the sequence of bases along the DNA determines the proteins that the cell can make. When you describe this, state that chromosomes are found in the nucleus, that they are made of DNA, and that they carry genetic information. For example, a human body cell has 23 pairs of chromosomes, with one chromosome of each pair inherited from each parent. A strong answer earns marks for these points. DNA is contained in structures called chromosomes. Chromosomes are found in the nucleus of eukaryotic cells. A chromosome is made of a long DNA molecule associated with proteins. Chromosomes carry genetic information in the sequence of bases. A common slip: Saying that chromosomes are made only of protein. Instead, stating that chromosomes contain DNA and associated proteins. Exam tip: Use the phrase chromosomes are found in the nucleus when describing location.
Key words
Say what each word means before you turn the card.
Chromosomes
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Chromosomes and inheritance
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Genes and genetic information
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See every definition
- Chromosomes
- Structures in which the DNA is contained, found in the nucleus of eukaryotic cells.
- Chromosomes and inheritance
- Human body cells contain 46 chromosomes arranged as 23 pairs, with one chromosome of each pair inherited from each parent.
- Genes and genetic information
- Each chromosome carries many genes, and the sequence of bases along the DNA determines the proteins that the cell can make.
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