Chapter 8, Section 1: Genetics Objectives: 1. Determine how traits are passed from parent to offspring. 2. Design and complete a Punnett Square.

Inheriting Traits An organisms is a collection of traits, all inherited from its parents. Heredity is the passing of traits from parent to offspring. Genes on chromosomes control an organism’s form and function or traits.

What is genetics? Genetics: the study of how traits are inherited through the interactions of alleles Alleles: the different forms of a trait that make up a gene pair When a pair of chromosomes separates through meiosis, alleles for each trait separate in different cells.

Mendel- the father of genetics Gregor Mendel was an Austrian monk, who noticed a connection between color of a pea plant flower, and the type of seed that was produced.

Genetics in the Garden Mendel studied 7 traits, and crossed two plants with different expressions for a trait, and realized that the offspring all looked like one of the parents. He called these plants hybrids, because they received different genetic information, or different alleles for a trait from each parent.

Dominant and Recessive Factors Mendel found that certain traits occurred more frequently than others. Mendel called the traits that occurred more frequently: dominant, because they “dominated” or covered up the others. He called the other traits recessive, because they “recessed” or seemed to disappear.

Punnett Squares Punnett Square: a tool used to predict results in genetics Letters are used to represent dominant and recessive alleles. They show the genotype, or the genetic makeup, of an organism. The way an organism looks is it’s phenotype, or physical appearance.

Alleles Determine Traits Most of the cells in your body have two alleles for every trait. They are located on similar chromosomes in the nucleus. An organism with the same alleles for a trait is said to be homozygous. An organism with different alleles for a trait is said to be heterozygous.