Name: _________________________________________________ Date: _______________ Period: ________ Biology Notes: Meiosis Directions: Fill in as we cover the topic in the PowerPoint. Corresponds to pages 173 – 176 in your textbook. What is Meiosis? • Defined: Process where the __________________ number is ________________ by ______________. • ___________________ created (egg & sperm) • End Result: ____________ _____________ Cells Interphase: • ____________ process that we’ve learned before. - G1: growth, _______________ functions, _______________ created. - S: ____________________ duplicated - G2: ________________ and normal functions. Prophase I: • _____________________ as mitosis, except… • Two Events: - 1) ______________________: Pairing of _____________________________ chromosomes • Dad’s #1 chromosome _______________ with Mom’s #1, etc… • The ___________________ paired chromatids equals a ____________________ - 2) ______________________: Exchange of genes - *Important for sexual reproduction & variation* Metaphase I: • _______________________ chromosomes (___________) align along cell __________________ Anaphase I: • Tetrads ____________________ • ______________________ chromosomes are pulled to _________________ ends Telophase I: • Cytokinesis __________________ the cells (cytoplasm) • Each ___________ contains _______ of the __________________ chromosomes • _____________________: 23 full chromosomes each No Interphase 2: • The Point of Meiosis: – _______________ the amount of chromosomes by _______________ • If Interphase 2 were to happen… – DNA would be duplicated AGAIN during the S stage Prophase II: • ________________________ as mitosis • Note:_______ __________ DNA was created (no 2nd interphase) Metaphse II: • _________________________ chromosomes are aligned at cell ____________________ Anaphase II: • Sister _______________________ are pulled to opposite ends. Telophase II: • _________________ divides the cells • Nucleus ___________________on the four new cells • _____________________ uncoil • End Result: _____________ ___________________ cells What is Spermatogenesis? • Defined: Production of ________________cells • Location: male ________________ • Makes final ________________ to sperm cell • ______________ haploid sperm ____________at a time What is Oogenesis (oh‐uh‐jen‐uh‐sis)? • Defined: Production of the ____________ cell (____________) - In female ____________________ • During meiosis I: __________________ distributed ______________________ • After meiosis II: - ___________ cell matures - 3 “__________________________”dissolve Comparison of Mitosis and Meiosis Mitosis • Division of ________________________ cells • Ex: Blood cells, skin cells, nerve cells… • End Result: 2 _____________________________________ • Importance: __________________ aging cells • Importance: Form of _______________ reproduction Review 1) Name three ways that meiosis and mitosis differ. Meiosis • Division of ____________________________ • Ex: Sperm and Egg cells • End Result: 4 _____________________________________ • Importance: _________________ the gamete chromosome _______________ by _______________ 2) Pick a stage of meiosis…any stage. Describe what happens in it. 3) What type of cells does meiosis create? 4) What are homologous chromosomes? 5) When do homologous chromosomes move to opposite ends of the cell? 6) When do chromatids move to opposite ends of the cell? 7) Why is no DNA created in meiosis 2? 8) How does meiosis differ in males vs. females?