in pteridophyta, asexual reproduction occurs by spore formation and sex u all reproduction occurs by zygote formation. explain plz.........
Answers
Answer:
Life cycle of Pteridophytes exhibit alternate generations between Gametophytes (sexual) and Sporophytes (asexual).
Explanation:
The plant life cycle begins as spore. The spore grows into small gametophyte or prothallium (vegetative structure) bearing rhizoids.
Gametophytes:
Gametophytes occur on soil surface (with help of mycorrizhal fungi). The sex organs are called Antheridia (male - sperm) and Archegonia (female - egg). The sperm swims in water to the egg and fertilization occurs. Thus, the zygote is formed. The zygote further divides and develop into embryo, which develops the first leaf, root and stem apex.
Sporophyte:
At maturity stage of plant, sporangia (cases which bears spores) are formed. In sporangia, the mother spore cells divide by meiosis, producing more spores. Thus, the sporangia burst opens and the spores are spread and again the life cycle starts.