Bellwork: What is the difference between a dominant gene and a recessive gene?

 Cells are the basis of genetic activity  Basic structure of all living things  All plant and animal life begins as a single cell  The nucleus contains pairs of chromosomes on which genes rests at specific locations

 Animal growth and reproduction takes place via cell division  Mitosis: Simple cell division for growth  DNA replicates and then is passed on to each divided cell

 Meiosis: Cell division that results in the formation of gametes or sex cells  Chromosomes divide and one is passed on to each new cell  A chromosome from each parent combines with the chromosome from the other parent and genetic recombination occurs

 Genes- units of genetic material  Genes occur at specific locations on chromosomes  In pairs of genes the genes may be alike or different

 Homozygous- pairs of genes that are alike  Heterozygous- pairs of genes that are different  When two genes in a pair are different, one usually expresses itself while the other does not …..dominant vs. recessive

 Genotype- the actual configuration of genes  Phenotype- Physical appearance of the animal

 Eye Color- Brown Dominant; Color Recessive  Tongue rolling- Can roll Dominant; Cannot Roll; Recessive  Thumbs- Straight Thumb Dominant; Curved Thumb Recessive

 2 Individuals one can roll their tongue and the other cannot  Male can roll his tongue and has a heterozygous genotype Rr  Female cannot roll her tongue and has a homozygous genotype rr