Schematically represent life cycle of a gymnosperm
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Word gymnosperms, gymnos − naked, sperma − seeds
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Ovules not enclosed by any ovary wall
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Seeds formed after fertilization are not covered (i.e., naked).
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Spores produced within sporangia, borne on sporophylls, which form strobili or cones o
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Male and female strobili may be borne on same tree ( Pinus ) or on different trees (Cycas).
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Megaspore mother cell divides mieotically to form four megaspores.
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Megaspore mother cell is a differentiated cell of nucellus. Nucellus protected by envelopes is known as an ovule.
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Male and female gametophytes do not have independent existence, hence remain within sporangia.
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Steps in fertilization:
Pollen grain released from microsporangium
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Carried by air currents
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Come in contact with ovules
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Discharge of pollen content on mouth of archegonia
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Fertilization
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Formation of zygote
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Development of naked seed
Refer to the below diagrams too.
It can also be represented as
Hope this will clear your doubts.
Regards