Question
Gemmae are present in [NEET 2021]
(a) mosses
(b) pteridophytes
(c) some gymnosperms
(d) some liverworts
Answer/Explanation
Ans. (d)
Some liverworts reproduce asexually by fragmentation of thalli or by the formation of gemmae. (green, multicelluar asexual buds). The gemmae are held in special organs known as gemma cups and are dispersed by rainfall.Gemmae becomes detached from parent body and germinate to form new individuals.
Question
Which of the following is responsible for peat formation? [CBSE AIPMT 2014]
(a) Marchantia
(b) Riccia
(c) Funaria
(d) Sphagnum
Answer/Explanation
Ans. (d)
Peat is mainly an accumulation of partially decayed vegetation or organic matter and Sphagnum accumulations can store water, since both living and dead plants can hold large quantities of water and living matter (like meat) for long distance transport inside their cells hence, it is responsible for peat formation.
Question
37 Which one of the following is common to multicellular fungi, filamentous algae and protonema of mosses? [NEET 2013]
(a) Diplontic life cycle
(b) Members of kingdom-Plantae
(c) Mode of nutrition
(d) Multiplication by fragmentation
Answer/Explanation
Ans. (d)
Multicellular fungi, filamentous algae and protonema of mosses all show multiplication by fragmentation.
Question
Archegoniophore is present in [CBSE AIPMT 2011]
(a) Chara
(b) Adiantum
(c) Funaria
(d) Marchantio
Answer/Explanation
Ans. (d)
In Marchantia, a bryophyte, the archegonia (female sex organs) are borne on special branches called archegoniophore or female receptacles. Each archegoniophore has rows of archegonia protected by involucre or perichaetium.
Question
39 Male and female gametophytes are independent and free-living in [CBSE AIPMT 2010]
(a) mustard
(b) castor
(c) Pinus
(d) Sphagnum
Answer/Explanation
Ans. (d)
In Sphagnum, male and female gametophytes are independent and free living. In bryophytes, the most conspicuous phase in life cycle is the gametophyte. It is independent and concerned with reproduction.
Question
In the prothallus of a vascular cryptogam, the antherozoids and eggs mature at different times, as a result [CBSE AIPMT 2007]
(a) there is no change in success rate of fertilisation
(b) there is high degree of sterility
(c) one can conclude that the plant is apomictic
(d) self fertilisation is prevented
Answer/Explanation
Ans. (d)
In the prothallus of a vascular cryptogam, the antherozoids and eggs mature at different times. As a result self fertilisation is prevented.
Question
Spore dissemination in some liverworts is aided by [CBSE AIPMT 2007]
(a) elaters
(b) indusium
(c) calyptra
(d) peristome teeth
Answer/Explanation
Ans. (a)
Elaters are hygroscopic in nature and help in dispersal of spores.
Question
Peat moss is used as a packing material for sending flowers and live plants to distant places because [CBSE AIPMT 2006]
(a) it is hygroscopic
(b) it reduces transpiration
(c) it serves as a disinfectant
(d) it is easily available
Answer/Explanation
Ans. (a)
Sphagnum is a bryophyte, commonly called as bog moss or peat moss. It is hygroscopic and possesses a remarkable water holding capacity. Hence, it is used as a packing material in the transportation of flowers, live plants, tubers, bulbs, seedlings, etc. It is also used in seed-beds and in moss-sticks.
Question
The antherozoids of Funaria are [CBSE AIPMT 1999]
(a) aciliated
(b) biflagellated
(c) multiciliated
(d) monociliated
Answer/Explanation
Ans. (b)
The antherozoids of Funaria are spirally coiled and bear two equal flagella at anterior end.
Question
Dichotomous branching is found in [CBSE AIPMT 1999]
(a) fern
(b) Funaria
(c) liverworts
(d) Marchantio
Answer/Explanation
Ans. (d)
Though many liverworts are dichotomously branched but some of the leafy liverworts are not. However, Marchantia is a liverwort which is dichotomously branched.
Question
Bryophytes comprise [CBSE AIPMT 1999]
(a) sporophyte of longer duration
(b) dominant phase of sporophyte which is parasitic
(c) dominant phase of gametophyte which produces spores
(d) small sporophyte phase generally parasitic on gametophyte
Answer/Explanation
Ans. (d)
Bryophyta is a group of thalloid, non-vascular, cryptogams which have gametophytic (haploid phase) as dominant phase. It bears diploid sporophytic phase which takes food from gametophytic phase, thus behaves as parasite on gametophyte.
Question
Which of the following is true about bryophytes? [CBSE AIPMT 1999]
(a) They possess archegonia
(b) They contain chloroplast
(c) They are thalloid
(d) All of the above
Answer/Explanation
Ans. (d)
Bryophytes are non-vascular cryptogams, their main plant body is gametophytic (haploid) which is a thalloid structure. It contains chlorophyll for the process of photosynthesis. Thalloid plant body bear archegonia as female sex organs.
Question
Bryophytes are dependent on water because [CBSE AIPMT 1998]
(a) water is essential for fertilisation for their homosporous nature
(b) water is essential for their vegetative propagation
(c) the sperms can easily reach up to egg in the archegonium
(d) archegonium has to remain filled with water for fertilisation
Answer/Explanation
Ans. (c)
The antherozoids (sperms) of bryophytes are flagellated (motile) and need a film of water to swim through for reaching the archegonium. Bryophyta is a group of cryptogams. Main plant body of bryophytes is gametophytic (haploid). It bearing male and female sex organs.
Question
Bryophytes can be separated from algae because they [CBSE AIPMT 1997]
(a) are thalloid forms
(b) have no conducting tissue
(c) possess archegonia with outer layer of sterile cells
(d) contain chloroplasts in their cells
Answer/Explanation
Ans. (c)
Archegonia is female sex organ in bryophytes. It is a flask-shaped multicellular organ. It is composed of a cylindrical upper portion called neck with a single layer of sterile cells called Neck Canal Cells (NCC) and a lower swollen sac-like portion called venter. It also has layer or layers of sterile cells. Venter encloses a larger egg cell and a smaller (just above to egg) Venter Canal Cell (VCC).
Question
Multicellular branched rhizoids and leafy gametophytes are characteristics of [CBSE AIPMT 1997]
(a) all bryophytes
(b) some bryophytes
(c) all pteridophytes
(d) some pteridophytes
Answer/Explanation
Ans. (b)
In pteridophytes and gymnosperms, gameto-phyte generation is reduced, sporophyte is well-developed. In bryophytes, gametophyte constitutes the main well developed generation but in mosses, (e.g. Funaria), it is foliose.
Question
In which one of these the elaters are present along with mature spores in the capsule (to help in spore dispersal)? [CBSE AIPMT 1996]
(a) Riccia
(b) Marchantia
(c) Funaria
(d) Sphagnum
Answer/Explanation
Ans. (b)
In Marchantia, capsule (the part of sporophyte) contains elaters $(2 n)$ and spores $(n)$ in tetrads. Elaters are diploid, spindle shaped hygroscopic elongated structures with 2 spiral bands. They show twisting movement and assist in spore dispersal on maturity.
Question
The plant body of moss (Funaria) is [CBSE AIPMT 1995, 2006]
(a) completely sporophyte
(b) completely gametophyte
(c) predominantly sporophyte with gametophyte
(d) predominantly gametophyte with sporophyte
Answer/Explanation
Ans. (d)
Funaria (green moss) and other bryophytes show alternation of generation with haploid gametophytic (n) and diploid sporophytic phases (2n). Plant body represents the gametophytic phase, which reproduces by producing gametes and on fusion form zygote.
Zygote develops into sporophyte and produces haploid meiospores which on germination form gametophyte.
Sporophyte in mosses is differentiated into foot, seta and capsule.
Question
Unique features of bryophytes is that they [CBSE AIPMT 1994]
(a) produce spores
(b) have sporophyte attached to gametophyte
(c) lack roots
(d) lack vascular tissues
Answer/Explanation
Ans. (b)
The main plant body of bryophytes is gametophytic which is independent and may be thallose or foliose. The sporophyte is differentiated into foot, seta and capsule and is partially or fully dependent upon the gametophyte.
Question
The plant group that produces spores and embryo but lacks vascular tissues and seeds is [CBSE AIPMT 1992]
(a) Pteridophyta
(b) Rhodophyta
(c) Bryophyta
(d) Phaeophyta
Answer/Explanation
Ans. (c)
Bryophytes consist of thalloid body, attached to the substratum by hair-like structures called rhizoids (true roots are absent), these lack vascular tissue (xylem and phloem) and require water at the time of fertilisation. Bryophytes exhibit alternation of generation. The haploid gametophyte (producing gametes for sexual reproduction) alternates with diploid sporophyte (producing spores for asexual reproduction). Production of large number of spores is for increasing the chances of survival and is an adaptation to land conditions.
Question
Which one has the largest gametophyte? [CBSE AIPMT 1991]
(a) Cycos
(b) Angiosperm
(c) Selaginella
(d) Moss
Answer/Explanation
Ans. (d)
Of the given options, moss has the largest gametophyte. It get reduced in the order as Selaginella, Cycas, angiosperms. Gametophyte begins with the haploid spore and ends with the formation of haploid gametes.
Gametophyte gives rise to the sporophyte (through sexual reproduction) and sporophyte gives rise to gametophyte. As one moves from thallophyte $\rightarrow$ bryophyte $\rightarrow$ pteridophyte $\rightarrow$ gymnosperms $\rightarrow$ angiosperms, there is development in the sporophyte and reduction in the gametophyte.
Question
Bryophytes are amphibians because [CBSE AIPMT 1991, 96]
(a) they require a layer of water for carrying out sexual reproduction
(b) they occur in damp places
(c) they are mostly aquatic
(d) All of the above
Answer/Explanation
Ans. (a)
Bryophytes are called amphibians (amphibians of plant kingdom). They are first amongst land plants which occur in damp and shady habitats. As vascular tissues are absent, male gametes require a layer of water for swimming and fertilisation.
Question
Apophysis in the capsule of Funaria is [CBSE AIPMT 1990]
(a) lower part
(b) upper part
(c) middle part
(d) fertile part
Answer/Explanation
Ans. (a)
Capsule (the body containing spores) of Funaria is differentiated into-operculum (cap shaped 2-3 layered thick lid on the top); theca (middle fertile part) and apophysis (sterile, solid basal portion of the capsule having chloroplasts).
Question
Moss peristome takes part in [CBSE AIPMT 1990]
(a) spore dispersal
(b) photosynthesis
(c) protection
(d) absorption
Answer/Explanation
Ans. (a)
Peristome functions in the dispersal of the spores. Peristome constitutes rings of teeth like projections at the rim of the capsule of the mosses. In Funaria, peristome are 32 in number, arragned in two rings of 16 each (a) outer exostome and (b) inner endostome.
Question
Protonema occurs in the life cycle of [CBSE AIPMT 1990, 93]
(a) Riccia
(b) Funaria
(c) Chiamydomonas
(d) Spirogyra
Answer/Explanation
Ans. (b)
Protonema represents the juvenile stage of moss (Funaria). It is much-branched, green filamentous structure formed by the germination of spores, under favourable conditions. The protonema consists of (a) some slender rhizoids (b) a number of aerial green prostrate branches bearing small lateral buds which grow up into new moss gametophores.
Question
Sperms of both Funaria and Pteris were released together near the archegonia of Pteris. Only Pteris sperms enter the archegonia as [CBSE AIPMT 1989]
(a) Pteris archegonia repel Funaria sperms
(b) Funaria sperms get killed by Pteris sperms
(c) Funaria sperms are less mobile
(d) Pteris archegonia release chemical to attract its sperms
Answer/Explanation
Ans. (d)
In Dryopteris and Pteris, when fertilisation occurs, sperms are attracted by the chemical diffusing into the water from the mucilage exuded by the open necks of archegonia of the older prothalli, some of them make their way down the canal to the egg in the venter and only one of these enters the egg to accomplish fertilisation.