Question
Question: Vascular cryptogams or seedless vascular plants belongs to A. Bryophyta B. Pteridophyta C. Tha...
Vascular cryptogams or seedless vascular plants belongs to
A. Bryophyta
B. Pteridophyta
C. Thallophyta
D. Spermatophyta
Solution
Whisk fern, horsetails, lycopodium, selaginella, etc. are examples of seedless vascular plants. Instead of flowers or seeds, they produce spores that show alternation of generation.
Complete answer:
The predominant and most influential group of land plants is vascular plants or tracheophytes. They contain tissue which carries water and other substances all over the plant. About 260,000 tracheophyte species account for more than 90% of the earth's vegetation. By the late Devonian era, vascular tissue, well-defined leaves and root systems were being formed. With this gain, the height and scale of the plants have increased and will spread to all ecosystems.
Plants containing vascular tissue, but not developing flowers or seeds are known as seedless vascular plants. The plants replicate using haploid single cell spores instead of seeds or flower in seedless vascular plants like horsetails and ferns. In comparison to many seeds, the spores are very lightweight which makes it easy to disperse in the wind and for plants to extend to new habitats. Although seedless vascular plants have evolved into all kinds of environments, during fertilisation they still rely on water as sperm needs to swim on a layer of moisture to get to the egg. The life cycle of vascular seedless plants alternates with the diploid sporophyte in the haploid gametophyte process. The diploid sporophyte is the dominant phase, but the gametophyte is an inconspicuous organism, which is nevertheless still separate. There is a strong overlap in the dominant phase of the life cycle during plant growth. The ferns and horsetails belong to pteridophytes. So, vascular cryptogams or seedless vascular plants belong to pteridophytes.
Thus, the correct answer is option B. i.e., Pteridophytes.
Note: A diploid sporophyte with a haploid gametophyte alternates the life-cycle of seedless vascular plants. Seedless vascular plants reproduce in place of the seeds, by means of unicellular, haploid spores; light spores allow fast dispersion into the wind. These plants need water during reproduction for sperm motility and are therefore often found in damp surroundings.