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    Sexual Reproduction

    Uploaded by

    MerrylFrancisco
    The document discusses sexual reproduction in plants. It describes the structure of flowers and defines unisexual and bisexual flowers. The reproductive organs of flowers, namely stamens and carpels, are described. The process of sexual reproduction including pollination, pollen grain germination, fertilization, formation of fruit and seeds is explained. Self and cross-pollination are defined.

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    Download as PPTX, PDF, TXT or read online from Scribd

    Sexual Reproduction

    Uploaded by

    MerrylFrancisco
    23 views23 pages
    The document discusses sexual reproduction in plants. It describes the structure of flowers and defines unisexual and bisexual flowers. The reproductive organs of flowers, namely stamens and carpels, are described. The process of sexual reproduction including pollination, pollen grain germination, fertilization, formation of fruit and seeds is explained. Self and cross-pollination are defined.

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    SEXUAL REPRODUCTION.pptx

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    The document discusses sexual reproduction in plants. It describes the structure of flowers and defines unisexual and bisexual flowers. The reproductive organs of flowers, namely stamens and carpels, are described. The process of sexual reproduction including pollination, pollen grain germination, fertilization, formation of fruit and seeds is explained. Self and cross-pollination are defined.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    23 views23 pages

    Sexual Reproduction

    Uploaded by

    MerrylFrancisco
    The document discusses sexual reproduction in plants. It describes the structure of flowers and defines unisexual and bisexual flowers. The reproductive organs of flowers, namely stamens and carpels, are described. The process of sexual reproduction including pollination, pollen grain germination, fertilization, formation of fruit and seeds is explained. Self and cross-pollination are defined.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    of 23

    SEXUAL

    REPRODUCTION
    IN PLANTS
    Overview of floral organs
    Structure of the flower
    • It is the organ for sexual reproduction
    • It has sepals petals , stamens & carpels
    • Stamens & carpels are the reproductive parts of
    the flower which contain the germ cells
    Carpel/
    Flowers are of two types
    1. Unisexual flowers
    2. Bisexual flowers
    Unisexual flowers

    Flower which contains either stamen or


    pistil is called unisexual flower
    Ex-papaya , water melon
    Flower which
    contains both stamen
    & pistil is called
    Bisexual flower
    EX- Hibiscus ,
    Mustard
    Reproductive floral organs: female
    •
    Carpel or pistil – female
    • reproductive organ
    • Itcontains:
    Ovary – enlarged structure
    at the base of carpel/pistil
    where the ovules are
    located; it will become the
    • fruit after fertilization
    Ovules – contains female
    • Itgerm cell or egg cell.
    becomes carpel
    seed after fertilization or
    • Stigma – is where pollen pistil
    sticks to
    • Style – is the long tube
    that connects stigma toovary
    ovary
    Reproductive floral organs: male
    • Stamen – male floral organ
    • It consists of:
    • Anther – part of the stamen that
    produces pollen
    • Filament – stalk-like structure that
    holds anther
    • Pollen grain –male gametophyte
    which consist of male gametes
    Steps in sexual reproduction
    • 1. Pollination
    • 2. Germination of pollen grain
    • 3. Fertilization
    • 4. Formation of the fruit & seed
    POLLINATION
    • The transfer of
    pollen from the male
    anther to the female
    stigma
    NEED FOR POLLINATION
    • The male gamete
    present in the pollen
    grain fuses with the
    egg cell present in
    the ovule to form the
    zygote which
    produces a new plant
    • For this the pollen
    needs to be
    transferred from
    stamen to the stigma
    Types of pollination
    • 1. Self pollination
    • 2. Cross pollination
    Transfer of pollen
    grains from anther to
    the stigma of the same
    flower is called self
    pollination
    Transfer of pollen grains from anther to the
    stigma of the another flower is called cross
    pollination
    Pollen grain germination
    • After the pollen lands on
    the suitable stigma, it
    has to reach the female
    gamete present in the in
    the ovary
    • For this pollen grain
    germinates on the
    stigma & forms a pollen
    tube
    • It travels through the
    style & reaches the ovule
    present in the ovary
    Fusion of the male &
    female gametes is
    called fertilization
    It occurs inside the
    ovule
    Pollen grain germination & fertilization
    FORMATION OF THE FRUIT & SEED
    • After fertilization the zygote divides
    several times to form an embryo within
    the ovule
    • The ovule develops a tough coat & is
    gradually converted into a seed
    • The ovary grows rapidly to form a
    fruit
    • Sepals , petals, stigma, style fall
    down
    Double Fertilization
    • Double fertilization occurs: One
    sperm nucleus (1n) fertilizes the egg,
    producing a zygote (2n)  which
    becomes the plant embryo inside the
    seed
    • Another sperm nucleus fuses with the polar
    nuclei, resulting in a triploid endosperm (3n)
    • Endosperm
    o. is a source of food for the young
    embry
    Endosperm
    Structure of the seed

    •It has cotyledons


    •Radicle which gives root
    system
    Seed germination
    • The seed
    contains the
    future plant or
    embryo which
    develops into
    seedling under
    appropriate
    conditions. This
    process is called
    seed
    germination

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