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Flowers and ReproductionReproductionProduce offspring that have identical copies of the parental genes. Generate new individuals that are genetically different from the parents.Stable environment creates adaptabilityDiverse species survive better genetically than homogenous speciesAsexual reproduction reproduce easily but not good for dispersal.Sexual reproduction requires 2 individuals with diverse genes and maybe fit some may be not fit

Flowering Plant Life Cycle

S is diploid in their flowers, meiosis gives rise to haploid. Spores, megaspore and microspore then undergo mitosis to haploid gametophyte (plant) then produce gametes megagamete (egg) and microgamete (sperm) then fertilization to form zygote (2N) grow into sporophyte

Oogamy Microgametophyte (male) sperm smallerMegagametophyte (female) egg largeHeterospory has 2 types of spores microspores and megasporeAlternation of Generation has S and G in the life cycle alternation of heteromorphic generation 2 different organisms (alternants) S and G

Flower Structure Flower a stem with leaflike structures1.Appendages: sepals calyx, petals corolla, stamens androecium, carpels gynoecium, pedicel flower stalk, receptacle for attachmentComplete flower all four floral parts are present Incomplete flower when 1 or 2 parts are lacking2.Sepals - outermost modified leaves , protect the bud from bacteria and fungi, maintains humidity and protects the nectar; petalloid colored sepals for attraction3.Petals inner whorl, together with sepals is called the perianth, leaf like pigmented, no fibers, thin, for attraction.

4.Stamens male, produce pollen from the anther (2N) of 4 long columns of tissue containingthe mmc or microscope mother cells or microsporocytes that will undergo meiosis producing 4 microspores (N). Tapetum as nurse cells of microspore development, tetrad microspore also called pollen with intine (inner) wall and exine(outer) wall and of sporopollenin waterproof, resistant to chemicals and for protection from drying. It has germination pore with patterns (ridges, bumps, spines) all contribute to fossilize strength of the pollen.

5.Carpels femaleStigma catches the pollenStyle elevates the stigmaOvary produce the megasporeOvary wall, placenta, ovule funniculus, integument, micropyle, nucellus (megasporangium) as mmc or megasporocytes will undergo meiosis producing 4 megapores 3 degenarates 1 remains inside the carpel or ovule.

A.Gametophyte Development

B.FertilizationSyngamy plasmogamy fusion of protoplasmKaryogamy fusion of nucleiPollen tube (3 nuclei) style ovule micropyle 1 synergid Pollen breaks releasing 2 sperm cells, 1 sperm nucleus + 1 egg = zygote (2N) only nuclear genes, 1 sperm + polar nuclei =Endosperm (3N) mitosis without cytokinesis resulting to Thousand of nuclei later cytokinesis that nourishess the zygote C.Embryo and Seed Development

D.SeedMatured ovuleSeed as to endosperm1.Albuminous endosperm present e.g. monocot2.Exalbuminous no endosperm e.g. dicot seeds

E.Fate of the Megagametophyte

F.Fruit Development

G.PollinationTransfer of one pollen from one stigma to another