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Ch. 38 Flowering Plant Reproduction. I. Alternation of generations A. Dominant sporophyte B. Gametophyte lives on sporophyte , and is actually the flower . 1. Male portion is the stamen - the anther has the pollen
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I.Alternation of generations • A.Dominant sporophyte • B.Gametophyte lives on sporophyte, and is actually the flower. • 1.Male portion is the stamen- the anther has the pollen • 2.The female portion is the _carpel, the stigma is where the pollen lands • 3.Complete flowers have both male and female parts and are also called perfect flowers • 4.Incomplete flowers lack one ore more of the organs floral parts like grasses lack petals. • 5.A imperfect flower is missing the stamen or carpel. • 6.Microspores are male • 7.Macrospores are female
II.Fertilization • A.Prevention of self-fertilization • 1. Some plants are self-incompatible therefore they need to be fertilized by another’s sperm. • 2.Self-fertilization • B.Double Fertilization • 1.The pollen which lands on the stigma divides forming 2 nuclei. • 2.A tube grows from the pollen down the style to the ovary. • 3.One sperm fertilizes the egg • 4.The other sperm fertilizes 2 nuclei in the ovary creating a triploid cell which will grow into the endosperm. • 5.The egg becomes the zygote while the endosperm provides food when it is germinated.
C.The seed • 1.Hypocotyl-embryonic axis • 2.Radicle- embryonic root • D.The fruit • 1.The cereal you eat with milk is actually a fruit not a dry seed. • 2.Seeds can stay dormant for long periods of time. • 3.Imbibition-absorption of water which activates seed germination
Botanists call the strawberry a "false fruit," a pseudocarp. A strawberry is actually a multiple fruit which consists of many tiny individual fruits embedded in a fleshy receptacle. The brownish or whitish specks, which are commonly considered seeds, are the true fruits, called achenes, and each of them surrounds a tiny seed.
III.Asexual Reproduction • A.Plants can clone themselves by vegatative reproduction. (runners in strawberries) • B.Fragmentation-separation of parent plant into parts that can form new plants