Question

All statements are true about ferns except
A. The gametophyte is larger than the sporophyte.
B. The sori gives rise to the gametophytes.
C. Eggs are fertilized by sperm in the archegonia.
D. Ferns possess vascular tissue for the transport of water and minerals.
E. Male gametes depend on water for fertilization.

Answer 1

Ferns belong to Pteridophytes which are the first terrestrial plant groups to possess the vascular tissues, xylem, and phloem. Pteridophytes also include horsetails. Their main plant body is sporophyte and the spores develop into gametophytes. They are seen in cool, moist, damp, shady places as they require water for fertilization. They are grown for ornamental and medicinal purposes.

Complete answer:
The main plant body in pteridophytes is the diploid sporophyte which is differentiated into true root, stem, and leaves. All these organs possess well-differentiated vascular bundles, that is xylem and phloem. The xylem in pteridophytes lack vessels and phloem lack companion cells in them. The size of the leaves varies in different species of pteridophytes. Ferns have larger leaves or macrophylls while Selaginella has microphylls or small leaves. On the lower side of the sporophyte is a sporophyte, sporangia are seen.
A cluster of sporangia in ferns is called fern sori. Sporophylls are also seen as compact structures called strobili or cones. The haploid spore mother cells in the sporangium undergo meiotic division to form haploid spores. The spores germinate into a multicellular gametophyte called prothallus which is free-living and photosynthetic.
The gametophyte contains antheridia and archegonia which are male and female sex organs respectively. For the transfer of antherozoids or the male gametes into the mouth of archegonium , water is necessary. For the same reason, pteridophytes are found only in moist, cool, damp places. The fusion of the two gametes results in the formation of a zygote which then produces a multicellular sporophyte. It is the dominant phase in pteridophytes and is bigger in size than the gametophytes.

All the options are true about ferns except option (A), the gametophyte is larger than the sporophyte.

Note: The spores produced by pteridophytes can be of similar size or a different size. They are called homosporous and heterosporous respectively. Megaspores germinate into female gametophytes and microspores germinate into male gametophytes. In pteridophytes, the zygote develops into an embryo within the female gametophyte itself. This development in female structure is marked as the precursor of seed habit in plants and is evolutionarily significant.