4Male Reproductive Structure The stamen consists of two parts: Anther and FilamentThe anther is where meiosis occurs to produce haploid pollenThe filament is a stalk that supports the anther
5Female Reproductive Structure The pistil consists of the stigma, style and ovaryThe sticky stigma receives the pollen from the antherThe pollen grows a tube down through the styleMeiosis occurs in the ovary to produce haploid ovules
6Reproductive Structures Petals: colourfulstructures that attract pollinators.Sepals: surround and protect the flower bud.
7PollinationWind, insects or other animals transfer pollen from the anther of one flower to the stigma of anotherFlowers vary depending on pollination mechanism
9Pollination Vectors Wind Pollination: Dull, scentless flowers with reduced petalsBees/Butterfly Pollination: Brightcolor, nectaries, scent.They sip nectar, get pollen on coats,transfer pollen from flower to flowerBird Pollination: Nectaries, brightcolors, tube-like flowersMoth Pollination: White petals,open at nightFly Pollination:Rank odor, fleshcolored petals
10Pollen Grain Anther Sac Pollen grains contain two haploid cells produced through meiosis.1- The Tube cell – will grow the pollen tube.2- The Generative cell – will go through mitosis to create two sperm cells.
11OvaryEach ovule within an ovary has a micropyle (an opening for the pollen tube).The ovules’ megasporangium undergo meiosis to produce four haploid cells (3 die leaving 1 megaspore)The megaspore undergoes mitosis 3 times to produce 8 haploid cells within the embryo sac.
13FertilizationAfter pollen lands on the stigma, a pollen tube grows down through the style to ovaryGenerative cell creates the two sperm nucleiDouble fertilization occurs:one sperm fertilizes the eggone sperm the two polar nuclei together
14Result of Double Fertilization The sperm nucleus and egg nucleus join to form a 2n (diploid) embryoThe other sperm nucleus and the two polar nuclei join to form a 3n (triploid) endosperm. The endosperm is the food supply for the embryo.First link
15Seed and Fruit Development After fertilization, the petals and sepals fall off flowerOvary “ripens” into a fruitThe ovule develops into a seed
16Seed Dispersal Mechanisms- Allow plants to colonize new areas and avoid shade of parent plant Wind Dispersal - Flight mechanisms,like parachutes, wings, etc.Ex. Dandelion, maples, birchAnimal Dispersal - Fleshy fruits whichanimals eat, drop undigested seeds infeces or burrs which stick toanimals’ coats
17Gravity Dispersal - Heavy nuts fall to ground and roll ex. acornsWater Dispersal - Plantsnear water create floatingfruitsex. coconuts