The sporophyte is not free living but is dependent on gametophyte in the plant group:

Question

Accepted Answer

The correct option is 2: Bryophyte

Bryophytes, which include mosses, liverworts, and hornworts, hold a transitional position in plant evolution, making their life cycle a unique adaptation to land. The question highlights a defining feature of this group: the persistent, green, and independent plant body is the haploid **gametophyte** (n). The diploid **sporophyte** (2n), which develops after fertilization, is non-photosynthetic and structurally simpler. Crucially, this sporophyte remains permanently attached to the gametophyte and relies on it for its nutritional supply—including water, minerals, and synthesized organic food. It is thus accurately described as being non-free-living and partially parasitic upon the dominant gametophyte. This complete dependence of the sporophyte on the gametophyte is a key diagnostic characteristic that distinguishes bryophytes from all other higher plant groups.

The incorrect option is 1: Algae.
Algae, which are predominantly aquatic, exhibit diverse life cycles, but in many common forms, the plant body is haploid, and the diploid stage is limited to the single-celled zygote. The zygote immediately undergoes meiosis to restore the haploid condition (*zygotic meiosis*). Therefore, there is no prolonged, multicellular, and dependent sporophyte stage as seen in Bryophytes. In other algae that do show an alternation between multicellular sporophyte and gametophyte generations (like some brown algae), both the sporophyte and gametophyte are typically large, free-living, and nutritionally independent of each other.

The incorrect option is 3: Pteridophyte.
Pteridophytes (ferns, horsetails, etc.) represent a significant evolutionary step, as their life cycle is dominated by the diploid **sporophyte** (2n), which is the large, leafy, and independent plant we commonly see. This sporophyte is fully differentiated with true roots, stems, and vascular tissue, making it completely self-sufficient. While the small, heart-shaped gametophyte (prothallus) is free-living and independent, the sporophyte quickly outgrows its early dependence on the prothallus. Once mature, the sporophyte is clearly the dominant and independent generation, which is the reverse of the condition described in the question.

The incorrect option is 4: Gymnosperms.
Gymnosperms (conifers, cycads, ginkgo) are seed plants that have achieved a full terrestrial lifestyle, and their life cycle is overwhelmingly dominated by the massive, woody, and independent **sporophyte** (2n). The gametophyte generation has become drastically reduced in size and is entirely dependent on the sporophyte. The female gametophyte is retained and nourished within the ovule, and the male gametophyte is the pollen grain, a tiny, dispersed structure. In this group, the dependence is inverted: the microscopic gametophyte is retained and dependent upon the massive sporophyte.