Bryophytes (General) Questions in English

(B) $Riccia$ belongs to the group $Bryophyta$.
In bryophytes,the dominant,independent,and photosynthetic phase of the life cycle is the gametophyte.
The sporophyte is dependent on the gametophyte for nutrition and anchorage.
Therefore,the main plant body of $Riccia$ is the gametophyte.

(D) The archegonia in $Riccia$ are flask-shaped.
They consist of a basal swollen portion called the venter and a long,slender neck.
The entire structure is protected by a sterile jacket of cells.

(C) In $Riccia$,the gametophytic phase begins with the germination of a haploid spore into a thallus.
This gametophyte produces sex organs (antheridia and archegonia).
The antherozoids released from the antheridium enter the archegonium and fuse with the egg to form a diploid zygote $(2n)$.
The formation of the zygote marks the end of the gametophytic phase and the beginning of the sporophytic phase.

(B) The sporophyte of $Riccia$ is the simplest among the $Bryophytes$.
It consists only of a capsule,which lacks a foot and a seta.
Inside the capsule,the sporogenous tissue differentiates into spores and nutritive cells (nurse cells).
Unlike many other liverworts,$Riccia$ does not possess elaters.

(B) In $Riccia$,the sex organs (antheridia and archegonia) are multicellular,jacketed,and embedded within the dorsal surface of the thallus. This is a characteristic feature of the genus $Riccia$ within the class $Hepaticopsida$ (liverworts).

(D) $Riccia$ and $Marchantia$ belong to the class $Hepaticopsida$ (liverworts) of the division $Bryophyta$.
In these plants,the rhizoids are unicellular and unbranched structures that help in the absorption of water and minerals from the soil and provide anchorage to the thallus.
Therefore,the correct option is $D$.

(C) The lower surface of $Riccia$ bears two types of unicellular rhizoids: smooth-walled and tuberculate.
These rhizoids help in the fixation of the plant body to the substratum and in the absorption of water and minerals.

(B) In $Riccia$,the sporophyte is the simplest among bryophytes,consisting only of a capsule.
It is completely dependent on the gametophyte for nutrition,making it a total parasite.
Rhizoids in $Riccia$ are unicellular.
However,the statement that spores are released by the rupture of the sporangium is incorrect.
In $Riccia$,the spores are dispersed only after the decay of the capsule wall and the rupture of the calyptra.

(D) The sporophyte or sporogonium in $Riccia$ is a total parasite because it is completely dependent on the gametophytic generation for its nutrition and protection.
Unlike some other bryophytes (e.g.,$Funaria$),where the sporophyte may be partially dependent,the $Riccia$ sporophyte lacks chlorophyll and cannot perform photosynthesis,thus relying entirely on the gametophyte.

(A) In Bryophytes,including $Riccia$,the main plant body is the gametophyte,which is haploid $(n)$.
The sporophyte is diploid $(2n)$ and is physically attached to the gametophyte for nutrition and protection.
Since the sporophyte depends entirely on the gametophyte for its nutritional requirements,it is considered parasitic over the gametophyte.
This represents a heteromorphic alternation of generations,where the life cycle is described as diplohaplontic.

(C) In $Riccia$,the sporophyte is very simple and lacks specialized structures like elaters or peristome teeth for spore dispersal.
As the sporophyte matures,it remains enclosed within the calyptra.
The spores are released only after the death and decay of the surrounding thallus tissue and the calyptra.
External pressure or environmental factors then facilitate the liberation of the spores.

(A) The archegonium of $Riccia$ is a flask-shaped structure.
It consists of a neck and a venter.
The neck encloses a row of $4$ to $6$ neck canal cells.
The venter is a swollen basal portion that encloses one venter canal cell and one egg cell (oosphere).
Among the given options,the most accurate description for the standard structure of a $Riccia$ archegonium is $4$ neck canal cells,$1$ venter canal cell,and one oosphere.

(D) In $Funaria$,the sporophyte consists of a foot,seta,and capsule. The capsule is differentiated into three parts: the basal apophysis,the middle theca,and the terminal operculum. Stomata are present only in the epidermis of the apophysis region,which is the lower part of the capsule. These stomata facilitate gaseous exchange.

(C) In $Funaria$,the capsule is differentiated into three parts: the basal apophysis,the middle theca,and the terminal operculum.
Within the theca,there is a central,cylindrical,sterile portion known as the columella.
The columella provides mechanical support and helps in the conduction of water and nutrients to the developing spores.
Therefore,the correct option is $C$.

(D) In $Funaria$,the gametophyte consists of a leafy axis.
On the lower portion of the leafy gametophore,there are present branched,multicellular rhizoids.
These rhizoids are characterized by the presence of oblique septa,which distinguish them from the rhizoids of other bryophytes.

(A) In the plant kingdom,the size of the gametophyte shows a trend of reduction as evolution progresses from bryophytes to angiosperms.
$1$. In bryophytes like $Funaria$,the gametophyte is the dominant,independent,and photosynthetic phase.
$2$. In pteridophytes like $Selaginella$,the gametophyte is small and independent.
$3$. In gymnosperms like $Pinus$ and $Cycas$,the gametophyte is highly reduced and dependent on the sporophyte.
$4$. Among the given options,$Funaria$ (a moss) has the largest and most complex gametophyte compared to the others,which are vascular plants where the sporophyte is the dominant phase.

(B) The antherozoids (male gametes) in $Funaria$ are biflagellated,meaning they possess two flagella.
These structures are coiled and motile,which allows them to swim through a film of water to reach the archegonia for fertilization.

(C) In mosses like $Funaria$,the sex organs (antheridia and archegonia) develop at the apex of the stem. The antheridia are produced on the male branch,while the archegonia are produced on the female branch.

(C) The sporophyte of $Funaria$ is differentiated into three parts: $Foot$,$Seta$,and $Capsule$.
Inside the capsule,there is a central sterile region known as the $Columella$.
$Elaters$ are specialized hygroscopic structures involved in spore dispersal,which are typically found in the sporophytes of $Marchantia$ (liverworts) but are absent in the sporophyte of $Funaria$ (moss).

(C) The life cycle of $Funaria$ is not completed without water because the $Funaria$ belongs to the group Bryophyta,which are known as the amphibians of the plant kingdom.
In $Funaria$,the male gametes (antherozoids) are flagellated and motile.
These antherozoids require a film of water to swim from the antheridium to the archegonium to reach the egg.
Fertilization occurs only in the presence of water,leading to the formation of a zygote $(2n)$,which eventually develops into the sporophyte.

(B) $Funaria$ is a moss belonging to the group $Bryophyta$.
In $Funaria$,the plant body is attached to the substratum by multicellular,branched,and filamentous structures known as rhizoids.
These rhizoids possess oblique septa and help in the anchorage of the plant to the soil as well as in the absorption of water and minerals.

(C) The presence of two types of cells,namely hyaline cells (dead,empty,and water-storing) and green cells (chlorophyllous and photosynthetic),is a unique characteristic of the genus $Sphagnum$.
These cells are arranged in a specific pattern within the leaves of $Sphagnum$,which helps in water retention and absorption.
Therefore,$Sphagnum$ $papillosum$ is the correct answer.

(D) In $Funaria$,the male reproductive structure is known as the antheridium. The cluster of antheridia is surrounded by a rosette of specialized leaves known as the perigonium. Therefore,these leaves are called perigonial leaves. In contrast,perichaetial leaves surround the archegonial cluster.

(B) The correct answer is $B$. The $Calyptra$ is a haploid protective structure derived from the enlarged archegonial wall that covers the developing capsule in mosses and liverworts (bryophytes). It protects the sporophyte during its early development.

(D) Bryophytes are characterized by growth originating from a single apical cell. This cell undergoes repeated divisions to contribute to the plant's body development. The position of these apical cells can be either strictly terminal or subterminal.

(D) The sex chromosomes in plants were first discovered by $C.E. \text{ Allen}$ in $1917$ in the liverwort $Sphaerocarpos \text{ donnellii}$.
Liverworts belong to the group $Bryophyta$.
Since the options provided do not include $Bryophyta$, and $Sphaerocarpos$ is a bryophyte, this question is often found in contexts where the discovery is associated with early land plants. However, among the given choices, if we consider the broader classification of plant evolution, the discovery is historically significant in $Bryophyta$. Given the options, if this is a standard multiple-choice question, it is important to note that $Sphaerocarpos$ is a bryophyte.

(A) In $Riccia$,water is absorbed from the soil by rhizoids and transported to the assimilatory filaments through the process of osmosis.
This occurs because the cell walls and plasma membranes of the rhizoids and the cells of the assimilatory filaments act as semipermeable membranes,allowing water to move from a region of higher water potential to a region of lower water potential.

(B) The peristome teeth of mosses exhibit a movement known as $Xerochasy$.
These teeth are hygroscopic in nature.
When the capsule is dry,the teeth bend outward to facilitate the dispersal of spores.
When the capsule is wet,they curve inward to protect the spores.
Therefore,the movement related to the drying of the capsule is termed $Xerochasy$.

(B) The classification of bryophytes into three classes,namely Hepaticopsida (Liverworts),Anthocerotopsida (Hornworts),and Bryopsida (Mosses),was proposed by the German botanist Werner Rothmaler in $1951$. While Shiv Ram Kashyap is known as the 'Father of Indian Bryology' and contributed significantly to the study of liverworts,the specific three-class classification system is attributed to Rothmaler.

(B) In bryophytes,the main plant body is haploid $(n)$.
It produces gametes,hence it is called the gametophyte.
The sporophyte $(2n)$ is multicellular and dependent on the gametophyte for nutrition.
Therefore,the dominant,independent,and photosynthetic phase in the life cycle of bryophytes is the gametophyte.

(D) In $Riccia$,which is a member of the $Bryophyta$ group,the plant body is a gametophyte $(n)$,which is the dominant and independent phase.
The sporophyte $(2n)$ stage is dependent on the gametophyte for its nutrition and protection.
Since the sporophyte is dependent on the gametophyte,it is considered parasitic or semi-parasitic in nature.
Therefore,the correct statement is that the sporophyte stage is parasitic.

(C) In $Bryophytes$,the male gametes $(antherozoids)$ are flagellated and motile. They require a film of water to swim from the antheridium to the archegonium to reach the egg cell for fertilization. Therefore,water is essential for the fertilization process in $Bryophytes$.

(D) Vegetative propagation in Bryophytes occurs through various methods such as fragmentation,gemmae (e.g.,in Marchantia),and adventitious branches. Budding is a method of asexual reproduction typically associated with organisms like yeast or Hydra,and it is not considered a standard method of vegetative propagation in Bryophytes.

(A) In $Bryophytes$, the main plant body is the $Gametophyte$ (haploid).
After fertilization, the zygote develops into a $Sporophyte$.
The $Sporophyte$ is multicellular and remains attached to the $Gametophyte$ for nutrition, making it heterotrophic.
The $Sporophyte$ produces haploid spores through meiosis, but the structure itself is diploid.
Therefore, the $Sporophyte$ is the stage that is diploid and heterotrophic.

(B) The classification of bryophytes into three classes,namely Hepaticopsida (Liverworts),Anthocerotopsida (Hornworts),and Bryopsida (Mosses),was proposed by the scientist $Rothmaler$ in $1951$.

(A) Bryophytes are known as the amphibians of the plant kingdom because they require water for fertilization. They occupy a position intermediate between algae (which are mostly aquatic and lack complex tissue differentiation) and pteridophytes (which are the first vascular land plants). Among the given options,$Funaria$ is a moss,which belongs to the group Bryophyta,representing this evolutionary transition.

(C) The plant kingdom $Bryophyta$ is primarily classified into three classes:
$1$. $Hepaticopsida$ (Liverworts)
$2$. $Anthocerotopsida$ (Hornworts)
$3$. $Bryopsida$ (Mosses)
$Archaea$ is a domain of prokaryotic microorganisms and is not related to the plant kingdom $Bryophyta$.

(A) The plant body of $Bryophytes$ is more differentiated than that of algae. It is thallus-like and prostrate or erect,and attached to the substratum by unicellular or multicellular $rhizoids$. They lack true roots,stem,or leaves. They possess root-like,leaf-like,or stem-like structures. Therefore,the correct option is $A$.

(C) The plant body of bryophytes is haploid and represents the gametophytic phase.
It is typically thalloid (not differentiated into true roots,stems,or leaves) and is autotrophic,meaning it can perform photosynthesis.
Since the gametophyte is haploid and autotrophic,options $(A)$ and $(B)$ are incorrect.
Therefore,the correct characteristic among the given choices is that it is thalloid.

(D) In $Anthoceros$,vegetative reproduction primarily occurs through the formation of adventitious branches. These branches develop from the thallus and eventually detach to grow into new independent plants. Other methods in $Anthoceros$ include the formation of tubers and gemmae,but among the given options,adventitious branches are the correct mechanism for vegetative propagation.

(B) In $Bryophytes$,the main plant body is haploid $(n)$.
It produces gametes by mitosis,hence it is called the gametophyte.
The gametophyte is independent and autotrophic (photosynthetic).
The sporophyte is dependent on the gametophyte for nutrition and is diploid $(2n)$.

(C) Vascular tissues ($xylem$ and $phloem$) are absent in $Bryophytes$.
$Equisetum$ and $Selaginella$ are $Pteridophytes$, which possess vascular tissues.
$Thuja$ is a $Gymnosperm$, which also possesses vascular tissues.
$Anthoceros$ belongs to the class $Anthocerotopsida$ under $Bryophyta$, and therefore, it lacks true vascular tissues.

(B) Embryophytes are plants that produce embryos. Among the given options,Bryophytes are considered the simplest and most primitive group of embryophytes. They are the first group of land plants to evolve an embryo stage in their life cycle,although they lack true vascular tissues.

(B) The first land-inhabiting plants are considered to be the Bryophytes. Among the given options,$Anthoceros$ belongs to the class Anthocerotopsida (Hornworts) of Bryophyta. Bryophytes are often referred to as the 'amphibians of the plant kingdom' because they require water for fertilization but are the first group of plants to have successfully colonized land environments. $Selaginella$ is a Pteridophyte,$Parmelia$ is a lichen,and $Thuja$ is a Gymnosperm,all of which evolved later than the early Bryophytes.

(D) Bryophytes are often referred to as the 'amphibians of the plant kingdom'.
They were the first group of plants to successfully colonize land,although they still require water for fertilization.
While lichens are pioneer species in primary succession,bryophytes represent the first major group of land plants in evolutionary history.

(A) In $Bryophytes$, the main plant body is the gametophyte $(n)$.
The sporophyte $(2n)$ is multicellular and is attached to the gametophyte for nutrition and protection.
Therefore, the sporophyte is dependent or parasitic on the gametophyte.
Among the given options, $Anthoceros$ is a member of $Bryophyta$ (Hornworts).
$Selaginella$ is a $Pteridophyte$, $Fucus$ is an $Alga$, and $Cycas$ is a $Gymnosperm$.

(A) In the plant kingdom,the main plant body is a gametophyte in Bryophytes.
$Riccia$ belongs to the class Hepaticopsida (liverworts) of the division Bryophyta.
In Bryophytes,the haploid gametophyte is the dominant,independent,and photosynthetic phase of the life cycle.
In contrast,$Ferns$ (Pteridophytes) and $Bennettites$ (Gymnosperms) have a dominant sporophytic plant body.
$Fucus$ is an alga where the main plant body is a diploid sporophyte.
Therefore,$Riccia$ is the correct answer.

(C) In $Bryophytes$,the main plant body is a $gametophyte$ $(n)$.
The $sporophyte$ $(2n)$ is not free-living but is attached to the photosynthetic $gametophyte$ and derives nourishment from it.
Therefore,the $sporophyte$ is parasitic on the $gametophyte$.
$Funaria$ is a moss,which belongs to the group $Bryophyta$.
$Volvox$ and $Spirogyra$ are algae,and $Ectocarpus$ is a brown alga.

(B) Prof. Shiv Ram Kashyap $(1882-1934)$ is widely recognized as the 'Father of Indian Bryology'. He made significant contributions to the study of liverworts and mosses in the Himalayas and established the foundations of bryological research in India.

(D) Bryophytes are non-vascular land plants. They are autotrophic,meaning they produce their own food through photosynthesis. Fertilization in bryophytes is dependent on water because the male gametes (antherozoids) are flagellated and require a water film to swim to the female gamete (egg). $A$ key evolutionary feature of bryophytes is that the zygote does not undergo immediate reduction division (meiosis); instead,it develops into a multicellular sporophyte,which is an embryo. Thus,the formation of an embryo from the zygote is a characteristic feature of bryophytes.