Genetics and Behavior

Nature
Genetic building blocks

• Nearly all cells contain a nucleus which in turn contain chromosomes
• Chemical basis of heredity
• Genes direct an individual’s development by influencing protein production

• 23 pairs of chromosomes in each cell of the body
• With the exception of sperm and ovum

• Each pair of chromosomes have corresponding pairs of genes
• For example, you have a pair of genes responsible for eye color and a pair for hair color
• Genes can be dominate or recessive
• This pair could be homozygous or heterozygous
• Genotype vs. Phenotype

• Dominate genes always win
• Phenotype reflects the dominate trait but genotype my vary
• Recessive type only appears when both genes are recessive
• What are some other possible pairs of parents?