Jawapan

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2016-10-18T23:30:01+08:00
Sry I explain english

Pollen Grain
-pollen grain are male gametes produced in anther which consists of four pollen sacs
-each pollen sac contains hundred of pollen mother cells which is diploid
-each mother cells undergoes meiosis to form for haploid microspores called tetrad
-each tetrad develop into pollen
-the nucleus of each tetrad undergoes mitosis to form polls tube nucleus and a generative nucleus
-tetrad with surface adapted for dispersion and is now called pollen

Embryo sac
-embryo sac mother cell which is diploid undergoes meiosis to form four megaspores
-three of the megaspores degenerate, leaving only one in the ovule
- nucleus of megaspore undergoes mitosis three times to from eight haploid nuclei
-three of eight nucleic migrate to one end of the cell to form antipodal cells
-another two polar nuclei move to the centre
-one of three nuclei near the opening of micropyle develops into egg cell flanked by two synergid cells
- the structure formed is know ad embryo sac where the embryo will develop
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