What kind of cell did we start with in mitosis? Meiosis Definition: What was our definition for meiosis? Reduction division prefix mei means: to lessen Meiosis Basics process used by sexually reproducing organisms to form gametes or sex cells What kind of cell did we start with in mitosis? beginning cell is called a “germ cell” Somatic diploid cell A germ cell is specialized diploid cell cell end products are called “gametes” or sex cells

What kind of cells are gametes, haploid or diploid? Meiosis GAMETES Let’s talk about sex cells or gametes eggs female gametes are called ___________ sperm or pollen male gametes are called __________________ meiosis gametogenesis formation of gametes is called _________________ oogenesis formation of eggs: _________________ spermatogenesis formation of sperm: _________________ What kind of cells are gametes, haploid or diploid? all gametes are haploid cells or “n” cells

Meiosis Meiosis Basics con’t Germ Cell Is this cell diploid or haploid? 2n n Meiosis I n Are these cells diploid or haploid? n n n n Meiosis II

Meiosis 46 23 23 23 23 23 23 Human Meiosis

Let Review, What are the stage of Mitosis? Meiosis Stages of Meiosis Let Review, What are the stage of Mitosis? Meiosis I Meiosis II Interphase I Interphase II Early Prophase I Early Prophase II Late Prophase I Late Prophase II Metaphase I IPMATI I Metaphase II Interphase Anaphase I Anaphase II Early Prophase Telophase I IPMATI Telophase II Late Prophase IPMATI II Metaphase Anaphase Telophase

Meiosis Meiosis Overview

Meiosis spermatogenesis oogenesis

Meiosis Category Mitosis Meiosis Compare and Contrast Mitosis and Meiosis Category Mitosis Meiosis Nickname starting cell Starting cell (n or 2n) cells produced cells produced (n or 2n) # of cells produced Names of stages Normal cell division Reduction division somatic germ 2n 2n somatic gametes n 2n two four IPMATI IPMATI I IPMATI II

Meiosis: The video The Circle of Life 23 n n 23 46 2n 2n 2n 46 46 23 fertilization 46 zygote 2n mitosis 2n 2n meiosis 46 46 23 23 n n