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Sexual Reproduction in Cells (Meiosis!). What is involved with sexual reproduction in cells?. Your body has two types of cells Body cells Sex cells Human body cells have 46 chromosomes Sex cells have (½) half as many: 23 chromosomes. Sexual Reproduction. The human sex cells are:
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What is involved with sexual reproduction in cells? • Your body has two types of cells • Body cells • Sex cells • Human body cells have 46chromosomes • Sex cells have (½) half as many: 23 chromosomes
Sexual Reproduction • The human sex cells are: • Female: EGG CELL (23) • Male: SPERM CELL (23) • When the two sex cells come together, this is called FERTILIZATION • They create a new cell called a ZYGOTE 23 chromosomes from egg + 23 chromosomes from sperm = 46 chromosomes in human cell • This new cell goes through MITOSIS and the organism develops
Sexual Reproduction • Sex cells are produced by a process called MEIOSIS • Happens in reproductive organs of PLANT and ANIMAL cells
MEIOSIS • Meiosis is the creation of sex cells • In MEIOSIS, the nucleus divides TWICE • Meiosis I • Meiosis II • Stages in meiosis are the same as in mitosis, but they occur TWICE, to produce cells with HALF (½) amount of genetic information • What would happen in SEXUAL reproduction if the two cells produced in mitosis combined?
MEIOSIS I • All stages of meiosis I are the same as mitosis EXCEPT FOR metaphase I: • Metaphase I • Chromosomes line up beside each other instead of in a single line • For example: • Mitosis: - Meiosis: