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SEXUAL REPRODUCTION Chapter 4 lesson 1 Part 1. Reproduction of Organisms Why do living things reproduce?

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  • SEXUAL REPRODUCTIONChapter 4 lesson 1Part 1

  • Reproduction of OrganismsWhy do living things reproduce?

  • Sexual Reproduction and MeiosisWhat is sexual reproduction, and why is it beneficial?What is the order of the phases of meiosis, and what happens during each phase?Why is meiosis important?

  • sexual reproductiona type of reproduction in which the genetic materials from two different cells combine, producing an offspring.

  • GameteThe cells that combines to form offspringA reproductive cellA sex cellFormed by meiosisIn most organisms meiosis produces 1 of 2 types of gametes

  • 2 types of gametes Ova (singular-ovum) - female gametes; female sex cell(book calls them eggs)

    Sperm - male gametes; male sex cell

  • 2 types of gametes spermovum

  • Where are gametes formed?Testes male reproductive organsOvaries female reproductive organsIn reproductive organsThe female sex cell, an ovum, forms in an ovary.The male sex cell, a sperm, forms in the testis.

  • Fertilizationthe formation of a zygote from the union of 2 gametesThe process when a sperm and an ovum join togther.

  • What is sexual reproduction? (cont.)During a process called fertilization, an ovum cell and a sperm cell join together to create a zygote.

  • ZygoteThe new cell that forms from fertilization

  • Diploid cellsOrganisms that reproduce sexually form somatic (body) cells and germ (gametes; sex) cells.In somatic cells of most organisms, similar chromosomes occur in pairs.Diploid cells are cells that have pairs of chromosomes.

  • Diploid cells

  • Pairs of chromosomes that have genes for the same traits arranged in the same order are called homologous chromosomes.Because one chromosome is inherited from each parent, the chromosomes are not identical.Different organisms have different numbers of chromosomes.Diploid cells

  • Homologous chromosomes

  • Haploid cellsHaploid cells are cells that have only one chromosome from each pair of chromosomes.haploidfrom Greek haploeides, means single

  • Haploid vs Diploid

  • Normal human cells have 23 pairs of chromosomes which is a total of 46 chromosomes. Human diploid number is 46Human haploid number is 23

  • Diploid & Haploid Examples

    HaploidDiploidHoney bee1632Crayfish100200Rabbit2244Watermelon1122Corn1020

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