Question

Which of the following have an independent gametophyte generation and a dependent sporophyte generation?
A. Horsetails
B. Mosses
C. Ferns
D. Conifers

Answer 1

Hint: In plants, alternation of generation occurs between the gametophyte stage and the sporophyte stage. In certain species, there occurs an independent gametophyte phase and dependent sporophyte stage. Such patterns can be observed in plants that belong to Bryophytes under the subdivision Musci.

Complete answer:
A stage in the life cycle of some plants and algae that begins with the union of gametes before the development of spores. The sporophyte is less well-formed than the gametophyte in liverworts, mosses, and hornworts. Moreover, the sporophyte is largely dependent on the gametophyte. Gymnosperm is conifers. They are cone-bearing, vascular-tissue seed plants. Woody plants are mostly living conifers, and the rest are palms. The live conifers are all in the Pinales order. Cedars, cypresses, firs, junipers, kauris, alligators, pines, redwoods, spruces, and yews are common examples.
While moss and hornwort sporophytes can perform photosynthesis, in order to maintain growth and spore production, they require extra photosynthate from the gametophyte. They rely on gametophytes for the supply of water, mineral nutrients and nitrogen. Independent gametophyte ferns are distinctive among vascular plants because they are sporophytes and replicate asexually in the gametophyte generation to sustain their populations.

So, the correct answer is option B.

Note: A haploid gametophyte with ‘n’ number of chromosomes alternates with a diploid multicellular sporophyte with 2n number of chromosomes: this life cycle (alternation between 2n and n stages) of plants is indicated by a term called ‘alternation of a generation’. The haploid phase of the plants is called the gametophyte phase, and the sporophyte is its diploid phase.