GENETICS Genes and Traits

WHAT’S A GENE?

1.Hereditary traits are determined by specific genes. 2. Individuals carry two genes for each trait, one from the mother’s egg and one from the father’s sperm. 3. When an individual reproduces, the two genes split up (segregate) and end up in separate gametes. The principle of segregation applies to all organisms, including humans.

WHAT’S A TRAIT?

A trait is a human being's behavior of doing something. A trait may learned or inherited.

1. Hereditary traits are determined by specific genes. Within the DNA molecule, genes exist that specify a certain, single characteristic; there is a gene for height, a gene for weight, and a gene for eye color, etc. Variations of the gene relating to the same trait are called alleles.

WHAT’S A TRAIT? 2. Individuals carry two genes for each trait, one from the mother’s egg and one from the father’s sperm. One of these two genes is dominant over the other. The dominant allele will mask the other, called the recessive allele. For example, if the father gives a tall allele of the height gene, and the mother gives a short allele, the offspring will be tall. This is because tall is dominant and short is recessive.