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Learn about the comparison between Male Gametophytes of Cycas and Male Gametophytes of Pinus.
Comparison # Male Gametophyte of Cycas:
1. Microspores, which develop into male gametophytes, are un-winged in Cycas.
2. Only one prothallial cell is present in cycas.
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3. In cycas the lone prothallial cell persists almost till the end of the male gametophyte development.
4. Pollination takes place at 3-celled stage in cycas, i.e. a prothallial cell, a generative cell and a tube cell.
5. Two motile male gametes, with several spiral bands of cilia, develop from generative cells in cycas.
6. Entire developmental process of male gametophyte in cycas completes within a few months.
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7. Pollen tube grows sideways in cycas into the tissue of the nucellus.
8. In cycas the pollen tube is haustorial in function.
Comparison # Male Gametophyte of Pinus:
1. in pinus microspores are winged.
2. Two prothallial cells are present in pinus.
3. In pinus prothallial cells start disintegrating even prior to pollination.
4. Pollination takes place at 4-celled stage in pinus, i.e. two prothallial cells, a generative cell and a tube cell.
5. there are two non-motile male gametes in pinus, without any cilia, develop from generative cell.
6. About one full year is required to complete the entire process of male gametophyte development in pinus.
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7. Pollen, tube hangs downwardly into the archegonial chamber of pinus.
8. In pinus pollen tube is sperm-carrier in function.
