When andwhere does reduction division take place in the life cycle of aliverwort, a moss, a fern, a gymnosperm and an angiosperm?
When andwhere does reduction division take place in the life cycle of aliverwort, a moss, a fern, a gymnosperm and an angiosperm?
Liverwort– In liverworts, the mainplant-body is haploid (gametophytic). It bears the male and femalesex organs which produce gametes. These gametes fuse to form azygote. The zygote develops on the gametophytic plant-body to form asporophyte. The sporophyte is differentiated into the foot, seta, andcapsule. Many haploid spores are produced as a result of thereduction division taking place inside the capsule.
Moss– In mosses, the primaryprotonema (developed in the first stage) develops into the secondaryprotonema. Both these stages are haploid or gametophytic. Thesecondary protonema bears the sex organs which produce gametes. Thesegametes fuse to form a zygote. The zygote develops into a sporophyte.Many spores are formed as a result of the reduction division takingplace in the capsule of this sporophyte.
Fern– In ferns, the main plant-bodyis sporophytic. Its leaves are known as sporophylls and these bearthe sporangia. Reduction division takes place in these sporangia,thereby producing many spores.
Gymnosperm– In gymnosperms, the mainplant-body is sporophytic. They bear two types of leaves –microsporophylls and megasporophylls. Reduction division takes placein the microsporangia present on the microsporophylls (producingpollen grains) and on the megasporangia present on themegasporophylls (producing megaspores).
Angiosperm– In angiosperms, the mainplant-body is sporophytic and bears flowers. The male sex organ inthe flower is the stamen, while the female sex organ is the pistil.Reduction division takes place in the anthers of the stamen(producing haploid pollen grains) and in the ovary of the pistil(producing eggs).
Liverwort– In liverworts, the mainplant-body is haploid (gametophytic). It bears the male and femalesex organs which produce gametes. These gametes fuse to form azygote. The zygote develops on the gametophytic plant-body to form asporophyte. The sporophyte is differentiated into the foot, seta, andcapsule. Many haploid spores are produced as a result of thereduction division taking place inside the capsule.
Moss– In mosses, the primaryprotonema (developed in the first stage) develops into the secondaryprotonema. Both these stages are haploid or gametophytic. Thesecondary protonema bears the sex organs which produce gametes. Thesegametes fuse to form a zygote. The zygote develops into a sporophyte.Many spores are formed as a result of the reduction division takingplace in the capsule of this sporophyte.
Fern– In ferns, the main plant-bodyis sporophytic. Its leaves are known as sporophylls and these bearthe sporangia. Reduction division takes place in these sporangia,thereby producing many spores.
Gymnosperm– In gymnosperms, the mainplant-body is sporophytic. They bear two types of leaves –microsporophylls and megasporophylls. Reduction division takes placein the microsporangia present on the microsporophylls (producingpollen grains) and on the megasporangia present on themegasporophylls (producing megaspores).
Angiosperm– In angiosperms, the mainplant-body is sporophytic and bears flowers. The male sex organ inthe flower is the stamen, while the female sex organ is the pistil.Reduction division takes place in the anthers of the stamen(producing haploid pollen grains) and in the ovary of the pistil(producing eggs).
