1. The Cell and Inheritance Objectives: Describe chromosomes and their role in inheritance. Identify and describe the events that occur during meiosis.

2. Vocabulary Sperm Egg Meiosis Questions: How many parent cells and how many daughter cells in Meiosis? How are mitosis and meiosis different in terms of types of cells?

3. Discovery in area of sex cells  Sutton 1903  Studied movement of chromosomes as sex cells developed in grasshoppers. egg- female sex cell sperm- male sex cell  Hypothesized-chromosomes were key to understanding how offspring come to have similar traits to parents.

4. MEIOSIS Chromosomes in body cells of grasshoppers 24 12 male chromosomes Chromosomes in sex cells of grasshoppers 12 12 female chromosomes 24 chromosomes ll ll ll ll ll ll ll ll ll ll ll ll ll 12 pair One each from male One each from female

5. ‘Chromosome Theory of Inheritance’ Chromosomes carry genes from one generation to the next. Question: How does the number of chromosomes in a grasshopper sex cell compare to the number in it’s body cells? Answer: Sex cells have exactly half the number. Question: How do they end up with half? Answer: Meiosis

6. Humans = 23 pairs

7. Meiosis and Punnett Squares XY Female parent cell XX Male Parent cell XY X X XXXY XXXY

10. How Meiosis Works: McGraw-Hill: Animated presentation Meiosis – The Continuation of Life ( 12 min. video clip)

11. Chromosome: The self-replicating genetic structure of cells containing the cellular DNA Gene: The fundamental physical and functional unit of heredity DNA (deoxyribonucleic acid): The molecule that encodes genetic information. DNA is in genes, genes are part of chromosomes

12. Different placement of genes on a chromosome

14. Cell & Inheritance Quiz Vocabulary: 1. a female sex cell 2. The process that occurs in sex cells by which the number of chromosomes is reduced by half. 3. a male sex cell Questions: 4.How many parent cells and how many daughter cells in Meiosis? 5.How are mitosis and meiosis different in terms of types of cells ?

15. Answers 2 pts. each 10 possible 1. egg 2. meiosis 3. sperm 4. one parent and 4 daughter cells in Meiosis 5. mitosis-growth and repair cells like skin. meiosis-sex cells, egg and sperm.