Question

In mosses gametophyte has 2 stages. What are these stages?
(a)$1^{ st }$ stage is sporogonium phase and $2^{ nd }$ protonema stage
(b)$1^{ st }$ stage is protonema and the $2^{ nd }$ stage is leafy stage
(c)$1^{ st }$ stage is gemmae formation and $2^{ nd }$ one is meiosis
(d)$1^{ st }$ stage is zygote and $2^{ nd }$ one is spore mother cell

Answer 1

There are 2 phases of gametophytes in mosses. The first stage is where a foot, seta and capsule are normally composed of the sporophyte of the bryophyte. It starts as a germ tube that lengthens and develops into a filamentous complex that, when a moss first grows from the spore, grows into leafy gametophores, the adult form of a gametophyte in bryophytes.

Complete answer:
In their lifecycle, plants have two distinct stages: the stage of gametophytes and the stage of sporophytes. In distinct multicellular structures, the haploid gametophyte produces the male and female gametes by mitosis. The diploid zygote, which grows into the sporophyte, forms a combination of the male and female gametes. The diploid sporophyte develops spores by meiosis after reaching maturity, which in turn splits by mitosis to create the haploid gametophyte. Gametes are created by the new gametophyte, and the cycle continues. This is the generation alternation, which is characteristic of the reproduction of plants.
When spores released from the sporophyte establish and start dividing, the gametophyte is formed. Sperm cells are able to migrate from one gametophyte to another and fertilise eggs when gametophytes are coated in a thin film of water. The fertilised egg then grows into a sporophyte, developing spores in turn. The gametophyte is the dominant generation, and due to the water and nutrients given by the gametophyte, the sporophyte is only able to survive. Unlike nearly all other land plants, this is the opposite.
A foot that anchors it to the gametophyte and helps to transfer water and nutrients from the gametophyte, a long erect stalk called a seta, and a pod-like capsule at the end where spores are produced. The sporophyte consists of three structures.
If spore falls into a damp area of field, it can germinate into a branching, threadlike filamentous protonema. Buds from the protonema then form, completing the life cycle, into leafy male or female gametophytes. A protonema is a thread-like cell chain that forms the earliest stage of the life cycle of mosses (the haploid stage).
So, the correct answer is, ‘$1^{ st }$ stage is sporogonium phase and $2^{ nd }$ protonema stage’.

Note: Mosses are a phylum of plants which are not vascular. Instead of seeds, they develop spores for reproduction and don't grow flowers, wood or true roots. Both species of moss have rhizoids instead of roots. Under the Music sub-group, the mosses sit within a class of plants called the Bryophyta.