Introduction to genetics: Difference between revisions

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{{Introduction to genetics glossary}}
 
'''Genetics''' is the study of [[genes]], and tries to explain what they are and how they work. Genes are how living [[organism]]s inherit features or [[Phenotypic trait|trait]]s from their ancestors; for example, children usually look like their parents because they have inherited their parents' genes. Genetics tries to identify which featurestraits are inherited, and explain how these featurestraits are passed from generation to generation.
 
In genetics, a feature of a living thing is called a "[[Phenotypic trait|trait]]". Some traits are part of an organisms' [[morphology (biology)|physical appearance]]; such as a person's eye-color, height or weight. Other sorts of traits are not easily seen and include blood types or resistance to diseases. Some traits are inherited through our genes, so tall and thin people tend to have tall and thin children. Other traits come from interactions between our genes and the environment, so a child might inherit the tendency to be tall, but if they are poorly nourished, they will still be short. The way our genes and environment interact to produce a trait can be complicated. For example, the chances of somebody dying of [[cancer]] or [[heart disease]] seems to depend on both their genes and their lifestyle.
 
Genes are made from long [[molecule]] called [[DNA]], which is copied and inherited across generations. DNA is made of [[nucleotide|simple unit]]s that line up in a particular order within this large molecule. The order of these units carries genetic information, similar to how the order of letters on a page carry information. The language used by DNA is called the [[genetic code]], which lets organisms read the information in the genes. This information is the instructions for constructing and operating a living organism.