MITOSIS AND MEIOSIS Important vocabulary Mitosis Nucleus Chromosome

MITOSIS AND MEIOSIS

Important vocabulary • Mitosis • Nucleus • Chromosome • Asexual reproduction • Meiosis • Sexual reproduction • Egg • Sperm • Haploid • Diploid

Mitosis vs. Meiosis Mitosis Asexual reproduction • In our bodies, cells are constantly damaged or dying • Mitosis is the process during which the nucleus of a cell divides to form two identical nuclei • Forming a new cell to replace a damaged or dead cell • This is a form of asexual reproduction because only one parent is present and produces an identical copy of itself Meiosis Sexual reproduction • Meiosis is the process during which a haploid sex cell is formed • This is a form of sexual reproduction because only two parents are required • Males provide the sperm • Females provide the egg • Haploid means only one set of chromosomes (in humans 23) • Diploid means two sets of chromosomes (in humans 46)

Mitosis vs. Meiosis Mitosis Meiosis Asexual reproduction Sexual reproduction One cell becomes two identical diploid body cells One cell becomes four different haploid sex cells

Mitosis vs. Meiosis Mitosis Meiosis Asexual reproduction Sexual reproduction One cell becomes two identical diploid body cells One cell becomes four different haploid sex cells The nucleus is divided once (mitosis) The nucleus is divided twice (meiosis I and meiosis II)

Phases of the Cell Cycle • Before the cell can undergo mitosis or meiosis, interphase takes place. This is the longest phase of the cell cycle, in which DNA doubles (makes a copy of itself). Mitosis Meiosis II Prophase II Metaphase II Anaphase II Telophase II • After the cell has completed telophase, the process of cytokinesis takes place. In this process, the cell’s membrane is pinched in two.