Sexual Asexual # Parents Division Type Benefit

Goal: Produce Reproductive Cells Meiosis: Goal: Produce Reproductive Cells Occurs in reproductive Organs Chromosome number reduced by half Begin with diploid cell (46 chromosomes) and finish haploid (23 chromosomes) Will Produce 4 sperm or one egg when completed Occurs in two mitotic stages

Replication Homologous Chromosomes

Homologous Chromosomes: Two chromosomes that code for the same genes, but don’t necessarily contain the same information (one from mom / dad) Separate during Meiosis I Sister Chromatids: Replicated chromosomes (identical) connected by a centromere Separate during Meiosis II

Meiosis I Meiosis II 1 N 2N                                                                                                                                                           http://www.phschool.com/science/biology_place/biocoach/meiosis/mei1ani.html

Meiosis I: Homologous Chromosomes Separate Become Haploid (with replicated copy) Meiosis II: Sister Chromosomes separate Haploid with correct chromosome number

Reproductive/Development Terms Fertilization union of sperm and egg Zygote Diploid result of sperm + egg Blastula Early stage resulting from mitosis Embryo weeks 1-8 in human development Fetus resembles adult form of human, after 8 weeks to parturition Dilation of Cervix beginning of opening of birth canal Parturition act of giving birth