NEET BIOLOGY

Detailed explanation-1: -This can be compared to the sexual reproduction in animals where both haploid and diploid cells are found in every generation. Plants alternate between the diploid sporophyte and haploid gametophyte, and between asexual and sexual reproduction. Therefore, the life cycle of plants is known as alternation of generations.

Detailed explanation-2: -Alternation of generations means that plants alternate between two different life stages, or generations, in their life cycle; a haploid stage called gametophyte and a diploid stage called sporophyte.

Detailed explanation-3: -This process is called plasmogamy. Actual fusion to form diploid nuclei is called karyogamy, and may not occur until sporangia are formed. Karogamy produces a diploid zygote, which is a short-lived sporophyte that soon undergoes meiosis to form haploid spores. When the spores germinate, they develop into new mycelia.

Detailed explanation-4: -Unlike animals(see Chapter 2), plants have multicellular haploid and multicellular diploid stages in their life cycle. Gametes develop in the multicellular haploid gametophyte (from the Greek phyton, “plant”). Fertilization gives rise to a multicellular diploid sporophyte, which produces haploid spores via meiosis.