Question

Gemmae are present in:

• A. Mosses
• B. Pteridophytes
• C. Some Gymnosperms
• D. Some Liverworts

Answer 1

The Correct Option is D

The question asks about the presence of gemmae, which are specific structures involved in asexual reproduction, commonly found in certain plant types.

Gemmae: Gemmae are small, lens-shaped structures that are involved in asexual reproduction. They can develop into a new individual without the need for fertilization.

Explanation of Options:

• Mosses: While mosses do employ asexual reproduction, gemmae are not typically the structures used for this purpose.
• Pteridophytes: Generally, pteridophytes reproduce through spores and do not utilize gemmae for asexual reproduction.
• Some Gymnosperms: Gymnosperms primarily reproduce through seeds and do not generally employ gemmae in their reproductive process.
• Some Liverworts: Liverworts, especially those within the genus Marchantia, are known for possessing gemmae as a means of asexual reproduction. These structures are produced in cup-like formations called gemma cups which facilitate the dispersal of gemmae.

The correct answer is Some Liverworts because these plants specifically use gemmae in structures known as gemma cups for asexual reproduction.

Thus, the presence of gemmae is a characteristic feature of some liverworts.

Answer 2

Reproduction can be classified into two types: asexual and sexual reproduction. Asexual reproduction involves the production of offspring through the simple division of cells, and it is commonly observed in single-cell organisms. This type of reproduction does not involve the fusion of gametes, and the offspring produced are genetically identical. Asexual reproduction is further classified into binary fission, budding, fragmentation, and sporogenesis. In the life cycle of plants, the spore-producing process is referred to as sporophyte. Plants have two reproductive stages: sexual and asexual. These two stages are segregated into the sporophyte and gametophyte through meiosis and fertilization. During the sporophyte phase, plants produce diploid (2n) spores that later develop into gametophytes and eventually into spores. Gemmae production is a widespread method of asexual reproduction in both mosses and liverworts. In liverworts like Marchantia, the flat plant body or thallus is a haploid gametophyte with gemma cups scattered in the upper part. The gemma cups are cup-like structures containing gemmae, which are small discs of haploid tissue. Gemmae directly give rise to gametophytes and are dispersed from gemma cups by rainfall. They may also be formed as outgrowths from the gametophyte portion and are referred to as exogenous gemmae. Hence, the correct answer is option D.