Gymnosperms Seed Plants Gymnosperms and the Seed 1.Overview of
Chap. 30 : Plant Reproduction I.Plant Reproductive Parts A. mosses and ferns : antheridium (male)...
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Transcript of Chap. 30 : Plant Reproduction I.Plant Reproductive Parts A. mosses and ferns : antheridium (male)...
Chap. 30 : Plant Reproduction
I. Plant Reproductive Parts
A. mosses and ferns : antheridium (male) and archegonium (female)
B. gymnosperms (conifers and ginkgo) : microspores (male) and megaspores (female)
C. angiosperms : flowering plants
1. Flower Parts
pollen
Male parts :1. Anther2. Pollen-sperm3. Stamen
Female parts :4. Stigma5. Pistil6. Ovary (eggs)
2. Pollen Formation
stigma
anther
stamen
Anther holds 4 pollen sacs each containing many microspores.
Makes 4 pollen grains, each with 2 sperm
3.Ovule (egg) formation
ovary
The ovum is the egg and is enlarged from absorbing all the divisions of the megaspores.
At the end of ovule formation there is an egg and 2 polar nuclei
4. Pollination – transfer of pollen from anther to stigma
Done by : wind, water, insects, birds, animals
5. Fertilization : Steps 1. Pollen gets on stigma forming a pollen
tube
2. Pollen tube connects stigma to embryo sac
3. 2 sperm travel to embryo sac
4. 1 sperm fertilizes egg to make zygote while other unites with polar nuclei to make endosperm (food for embryo) or (fruit for animals)
5. After fertilization the flower withers and drops off