Review: Meiosis

1. Sexual Reproduction and Genetics Chapter 10 Review: Meiosis Sperm Father’s Characteristics + Egg Mother’s Characteristics Zygote

2. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics Gregor Mendel’s Peas • Genetics – the scientific study of heredity • Gregor Mendel – a monk from Austria, and is known as the father of genetics • He did his most notable work with pea plants in his garden.

3. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • The passing of traits to the next generation is called inheritance, or heredity. • Mendel performed cross-pollination in pea plants. • Mendel followed various traits in the pea plants he bred. • A trait is a characteristic such as hair or eye color, and height.

4. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • The parent generation is also known as the P generation.

5. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • The offspring of this P cross are called the first filial (F1) generation. • The second filial (F2) generation is the offspring from the F1 cross.

6. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • Mendel studied seven different traits. • Seed or pea color – Yellow or Green • Flower color – Purple or White • Seed pod color – Yellow or Green

7. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • Mendel studied seven different traits. • Seed shape or texture – Round or Wrinkled • Seed pod shape – Inflated or Constricted • Stem length – Tall or Dwarf • Flower position – Axial or Terminal

8. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics Genes in Pairs • Allele • An alternative form of a single gene passed from generation to generation • Expressed as a letter • (A or a, B or b, etc.) • Found on the same location of homologous chromosomes.

9. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics Dominance • An organism with two of the same alleles for a particular trait is homozygous. • Example: AA or aa • An organism with two different alleles for a particular trait is heterozygous. • Example: Aa

10. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics Dominance • A dominant trait needs only one copy of an allele to express its phenotype. • A recessive trait requires two copies of an allele to express its phenotype.

11. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics Genotype and Phenotype • An organism’s allele pairs are called its genotype. • The observable characteristic or outward expression of an allele pair is called the phenotype.

12. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • Seed or pea color – Yellow or Green Seed color Phenotype Yellow or Green Seed color Genotype Yellow (YY or Yy) Green (yy)

13. Sexual Reproduction and Genetics Chapter 10 10.2 Mendelian Genetics • Seed or pea color – Yellow or Green Yellow is dominant to green!! A dominant allele will mask the expression of a recessive allele. You only need one dominant allele to represent yellow. Genotype Yellow (YY or Yy) Green (yy) YY or Yy Must have two yy.

14. Sexual Reproduction and Genetics Chapter 10 Genotype and Phenotype? 10.2 Mendelian Genetics Yellow is dominant to green.

15. Sexual Reproduction and Genetics Chapter 10 Genotype and Phenotype? 10.2 Mendelian Genetics Yellow is dominant to green.