1. Genetics: Inheritance

2. Meiosis: Summary
Diploid Cells (2n): two sets of chromosomes = “homologous chromosomes”
One set from each parent
normal body cells
Produced by mitosis
Haploid Cells (n): one set of chromosomes
Gametes or sex cells
Produced by meiosis
Meiosis: 2 rounds of cell division that produce cells with HALF the number of chromosomes

3. Mitosis vs. Meiosis

4. Some Definitions…. Genetics: The scientific study of heredity.
Trait: A specific characteristic of an individual.
Gene:
Sequence of DNA that codes for a protein (trait)
Passed down from parent to offspring
Allele: Different possible forms of a gene (one from each parent)
Homozygous: 2 of the same allele for the same gene
Heterozygous: different alleles for the same gene

5. Principle of Dominance
Definition: Some alleles are dominant and others are recessive
Which is the dominant allele for eye color, and which is the recessive?
Which are the dominant alleles and which are the recessive? How do you know?

6. Genotype vs. Phenotype
Genotype: the genetic makeup (i.e. combination of alleles for each particular gene)
Phenotype: the physical traits exhibited by an organism (observable)

7. Complete Dominance – Dominant allele is shown in heterozygous
Incomplete Dominance – blend between dominant and recessive
Co-Dominance – Two different alleles are represented

8. Meiosis: How do we get genetic diversity?
Crossing Over
Random Orientation
Fertilization

9. Recessive Genetic Disorders
What common trends might genetic disorders have? (Think about what DNA and genes CODE for!)
Examples: Cystic Fibrosis, Tay Sachs Disease, Albinism
If a genetic disorder is RECESSIVE, what does that mean?
How might completely healthy parents have a child with a recessive genetic disorder?