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Patterns of Inheritance - Windows to the Universe

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Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.

You Inherited Your Parentsí Genes!

Aunt Maggie says you have your father's eyes.
Grandma says you have your mother's smile.

Could you actually have the traits from these other people? If you are genetically related to them then yes, you could. Half of your genes are from your mother and half are from your father. But you might look more like one of them than the other. Why is that?

Within each of the trillions of cells in your body are chromosomes. Chromosomes come in pairs. You got one chromosome of each pair from your mother and one from your father. Along each chromosome are genes, one for each trait. This means that you have two copies of each gene, one from your mother and one from your father. Both genes of a pair deal with the same trait, but they might differ in their information about it. For instance, one gene for eye color might say blue while the other one says brown.

One of those genes wins out and its instructions are carried out. It's called the dominant gene. The other one is still present but its instructions are not carried out. It's called a recessive gene. As a custom, people designate dominant genes with uppercase letters and lowercase genes with lowercase letters. For example gene "A" is dominant and gene "a" is recessive.

The genes of an individual are called its genotype. They determine what it will look like, which is called its phenotype!

Last modified February 29, 2008 by Lisa Gardiner.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF