Genes, chromosomes and DNA: key definitions

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Biology

Genes, Chromosomes and DNA

1.) Most cells in your body have a nucleus- and its the nucleus that contains your genetic material.

2.) The genetic material in the nucleus is arranged into chromosomes. The human cell nucleus contains 23 pairs of chromosomes.

3.) Each chromosome is one very long molecule of DNA that's coiled up.

4.) A gene is a short length of a chromosome.

5.)Genes control the development of different characteristics, e.g hair colour, and how and organism functions

6.) Genes can exist in different versions. Each version gives a different form of characteristic, like blue or brown eyes. The different version of the same gene are called alleles.

Genes are instructions for cells

Each gene is a code for making a certain protein. Proteins are the building blocks of cells. Having different versions of proteins means that we end up with different characteristics

1.) Some proteins are structural proteins . They're part of things like, skin, hair, blood and the cytoplasm in our cells. E.g collagen is a structural protein that is found in tendons, bones and cartillage

2.)Other proteins are functional proteins. For example, enzymes are proteins that help with digestion by breaking down food molecules - amylase is a digestive enzyme that breaks down starch to maltose

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