Pteridophytes (General) Questions in English

(D) In Pteridophytes,the main plant body is a sporophyte,which is differentiated into true root,stem,and leaves. The gametophytic stage is small,inconspicuous,and multicellular,often referred to as a prothallus. Because it is small and short-lived compared to the sporophyte,it is considered a reduced stage.

(C) In Pteridophytes (ferns),the main plant body is a sporophyte,which is differentiated into true roots,stems,and leaves. This phase is long-lived and dominant.
In contrast,the gametophyte phase is small,inconspicuous,and often referred to as a prothallus (a thallus-like structure).
Therefore,the assertion that the sporophyte is dominant is true,but the reason stating that the sporophyte is a thallus is false,as the thallus structure is characteristic of the gametophyte phase.

(C) The plant body of $Pteridophytes$ is well-differentiated into true roots,stems,and leaves.
$Thallophyta$ (algae) have a thallus-like body without true roots,stems,or leaves.
$Bryophyta$ have root-like,stem-like,and leaf-like structures but lack true vascular tissues and true roots.
$Lichens$ are symbiotic associations between algae and fungi and do not possess true roots,stems,or leaves.

(A) The correct answer is $A$.
$1$. $Pteridophytes$ are typically found in cool,damp,and shady places,although some species may thrive in sandy soil conditions.
$2$. In $Pteridophytes$,the main plant body is the $Sporophyte$,which is differentiated into true roots,stems,and leaves.
$3$. These plants possess well-developed vascular tissues ($Xylem$ and $Phloem$).
$4$. Therefore,among the given options,$A$ is the correct characteristic of $Pteridophytes$.

(D) The plant kingdom is classified into various groups based on their structural complexity.
$1$. Thallophytes (Algae) lack differentiated plant bodies and vascular tissues.
$2$. Bryophytes are the first land plants but lack true vascular tissues ($Xylem$ and $Phloem$).
$3$. Pteridophytes are the first group of plants to possess well-developed vascular tissues ($Xylem$ and $Phloem$) for the conduction of water and nutrients.
$4$. Gymnosperms and Angiosperms also possess vascular tissues, but Pteridophytes were the first to evolve them.

(B) In Pteridophytes,the main plant body is a sporophyte,which is diploid $(2n)$ and produces spores. The gametophytic stage is a small,inconspicuous,but free-living,mostly photosynthetic thalloid structure called a prothallus. This stage is haploid $(n)$ and is responsible for the production of gametes (male and female sex organs). Therefore,it is considered a secondary or reduced stage compared to the dominant sporophytic phase.

(A) Pteridophytes are classified based on the type of spores they produce.
$1$. Homosporous pteridophytes produce only one type of spores,which are morphologically identical. Examples include $Dryopteris$,$Pteris$,and $Lycopodium$.
$2$. Heterosporous pteridophytes produce two types of spores: microspores and megaspores. Examples include $Selaginella$ and $Salvinia$.
$3$. $Equisetum$ is also generally considered homosporous.
$4$. $Rhynia$ is an extinct fossil pteridophyte,which was also homosporous.
However,in the context of standard $NCERT$ examples,$Dryopteris$ is a classic example of a homosporous pteridophyte,while $Selaginella$ is the primary example of a heterosporous one.

(B) Pteridophytes are generally homosporous,meaning they produce only one type of spore. However,some genera like $Selaginella$ and $Salvinia$ are heterosporous,as they produce two different types of spores: macrospores and microspores. $Dryopteris$ and $Equisetum$ are examples of homosporous pteridophytes,while $Rhynia$ is an extinct genus.

(A) In Pteridophytes,the main plant body is a sporophyte which differentiates into true root,stem,and leaves.
These leaves are known as sporophylls when they bear sporangia.
Inside these sporangia,spore mother cells undergo meiosis to produce spores.
Therefore,statement $S$ is true because spores are produced in sporangia,and statement $R$ is also true because these sporangia are borne on specialized leaves called sporophylls.
Since the production of spores in sporangia is directly facilitated by their location on sporophylls,$R$ is the correct explanation of $S$.

(A) Plants that produce only one type of spore are called $Homosporous$ plants. These spores germinate to produce gametophytes that may be monoecious or dioecious. In contrast,$Heterosporous$ plants produce two types of spores: microspores and megaspores.

(A) The plant kingdom is classified based on the presence or absence of vascular tissues and seeds.
$1$. Algae and Bryophytes lack specialized vascular tissues ($xylem$ and $phloem$).
$2$. Pteridophytes are the first terrestrial plants to possess vascular tissues ($xylem$ and $phloem$) and reproduce via spores, but they do not produce seeds.
$3$. Gymnosperms and Angiosperms are seed-bearing plants.
Therefore, Pteridophytes are the group that has vascular tissues and spores but is seedless.

(C) Pteridophytes are plants that reproduce by spores.
Based on the type of spores produced,they are classified into two categories:
$1$. Homosporous: Most Pteridophytes (e.g.,$Dryopteris$,$Adiantum$) produce only one type of spore.
$2$. Heterosporous: Some Pteridophytes (e.g.,$Selaginella$,$Salvinia$) produce two different types of spores,known as microspores and megaspores.
Therefore,Pteridophytes can be either homosporous or heterosporous.

(B) In $Pteridophytes$,the main plant body is a $sporophyte$ $(2n)$,which is differentiated into true root,stem,and leaves.
These plants produce sporangia that are subtended by leaf-like appendages called $sporophylls$.
Inside the sporangia,spore mother cells undergo $meiosis$ (reduction division) to produce haploid $(n)$ spores.
Therefore,meiosis occurs during the process of spore formation.

(D) The plant kingdom is classified into various groups such as Thallophyta,Bryophyta,Pteridophyta,Gymnosperms,and Angiosperms.
$Selaginella$,$Equisetum$,and $Salvinia$ are well-known examples of Pteridophytes.
$Polytrichum$ belongs to the group Bryophyta (specifically,it is a moss).
Therefore,$Polytrichum$ is not a pteridophyte.

(C) $Selaginella$ is a pteridophyte that is heterosporous,meaning it produces two types of spores: microspores and megaspores.
This heterospory is a significant evolutionary step towards the seed habit.
The strobili (cones) in $Selaginella$ are typically bisexual,containing both microsporangia and megasporangia,rather than being unisexual.
Therefore,the assertion $(A)$ is true,but the reason $(R)$ is false.

(D) In $Pteridophytes$, the main plant body is a sporophyte, which is diploid and differentiated into true roots, stems, and leaves.
The gametophyte (prothallus) is small, inconspicuous, multicellular, free-living, and usually photosynthetic.
However, in some specific contexts or when comparing with higher plants, the gametophyte is described as reduced and short-lived compared to the dominant sporophyte.
Among the given options, $Pteridophytes$ represent the group where the gametophyte is independent but significantly reduced compared to the sporophyte generation.

(D) The division $Pteridophyta$ is classified into four main classes based on the standard $NCERT$ biology curriculum.
These classes are:
$1$. $Psilopsida$
$2$. $Lycopsida$
$3$. $Sphenopsida$
$4$. $Pteropsida$
Therefore,the division $Pteridophyta$ contains $4$ classes.

(A) In $Pteridophytes$, the main plant body is a $sporophyte$, which is $diploid$ $(2n)$.
This $sporophyte$ is differentiated into true roots, stems, and leaves.
These organs possess well-differentiated vascular tissues ($xylem$ and $phloem$).
Therefore, the correct characteristic describing the main plant body is that it is $diploid$.

(C) $Nephrolepis$ is a genus of ferns,which are pteridophytes. Pteridophytes are cryptogams (non-flowering plants).
Therefore,Assertion $(A)$ is true.
However,$Nephrolepis$ is a pteridophyte,not a bryophyte. Bryophytes are a different group of plants (e.g.,mosses and liverworts).
Therefore,Reason $(R)$ is false.
Thus,the correct option is $C$.

(B) The correct matching is as follows:
$1$. $A$. Dryopteris (Fern) is a common Pteridophyte, which is homosporous $(s)$.
$2$. $B$. Selaginella is a heterosporous Pteridophyte $(r)$.
$3$. $C$. Equisetum is a homosporous Pteridophyte $(p)$.
$4$. $D$. Rhynia is an extinct fossil Pteridophyte $(q)$.
Thus, the correct sequence is $A-s, B-r, C-p, D-q$.

(A) The prothallus of a fern $(Dryopteris)$ is a heart-shaped,photosynthetic,independent gametophyte.
It is monoecious,meaning it bears both male and female sex organs.
The sex organs,namely the antheridia (male) and archegonia (female),are typically found on the ventral (lower) surface of the prothallus.
This location helps in the protection of the reproductive structures and facilitates fertilization,as the antherozoids require a film of water to swim towards the archegonia.

(D) In many Pteridophytes,the sporophylls (spore-bearing leaves) may form distinct compact structures called strobili or cones (e.g.,in Selaginella and Equisetum).
These structures are formed by the aggregation of sporophylls around a central axis.

(C) In pteridophytes,the main plant body is a sporophyte,which is differentiated into true root,stem,and leaves. This sporophyte is the dominant phase in their life cycle,whereas the gametophyte is small and inconspicuous. Therefore,the dominant phase is the plant body (sporophyte).

(C) In Pteridophytes,the main plant body is a sporophyte,which is differentiated into true root,stem,and leaves.
These organs possess sporangia that are subtended by leaf-like appendages called sporophylls.
In some cases,sporophylls may form distinct compact structures called strobili or cones.
The sporangia produce spores by meiosis in spore mother cells.
Since the sporophyte produces spores,it is responsible for spore formation,which is a key part of the asexual phase of their life cycle.
Therefore,both $(A)$ and $(B)$ are correct.

(B) In the life cycle of Pteridophytes,the plant body is a sporophyte,which is differentiated into true root,stem,and leaves.
These organs possess vascular tissues.
The sporophyte generation is the dominant phase in Pteridophytes.
Chromosomally,the sporophyte is diploid $(2n)$ because it is formed by the fusion of male and female gametes (fertilization).
Therefore,the correct option is $B$.

(A) In the life cycle of pteridophytes,the main plant body is a sporophyte,which is diploid $(2n)$.
The sporophyte produces spores through meiosis,which are haploid $(n)$.
These spores germinate to form a small,multicellular,free-living,photosynthetic thalloid structure called the prothallus.
The prothallus represents the gametophytic phase of the pteridophyte life cycle.
Since the prothallus develops from haploid spores via mitosis,the gametophytic phase is haploid $(n)$.

(B) In $Pteridophytes$,the main plant body is a sporophyte,which is differentiated into true root,stem,and leaves.
The gametophytic stage is small,inconspicuous,and free-living,which is known as the $Prothallus$.
The $Prothallus$ is a heart-shaped,photosynthetic,and multicellular structure that bears sex organs ($Antheridia$ and $Archegonia$).

(B) Pteridophytes are classified based on the type of spores they produce.
Most pteridophytes produce only one type of spore,known as homosporous (e.g.,Equisetum,Dryopteris,Pteris).
Genera like Selaginella and Salvinia are heterosporous,meaning they produce two kinds of spores: macrospores and microspores.
Rhynia is an extinct genus,but it is generally considered homosporous. However,in the context of standard biology curriculum,Equisetum is the classic example of a homosporous pteridophyte.

(B) The subphylum Pteridophyta is divided into four classes:
$1$. Psilopsida (e.g.,Psilotum)
$2$. Lycopsida (e.g.,Selaginella)
$3$. Sphenopsida (e.g.,Equisetum)
$4$. Pteropsida (e.g.,Dryopteris,Pteris,Adiantum)

(A) In Pteridophytes,the main plant body is a sporophyte,which differentiates into true root,stem,and leaves. The sporophytes bear sporangia that are subtended by leaf-like appendages called sporophylls. Inside the sporangia,spore mother cells undergo meiosis to produce spores. Thus,both statements are correct,and the presence of sporophylls explains the structural arrangement of sporangia in these plants.

(B) $Selaginella$ is a member of the $Pteridophyta$ division,not $Gymnospermae$. Therefore,statement $X$ is incorrect because it misclassifies the plant.
$Selaginella$ is indeed heterosporous,meaning it produces two different types of spores: microspores and megaspores. Thus,statement $Y$ is correct.

(A) The figure shows a prothallus of a fern (Pteridophyte).
In Pteridophytes,the male gametes (antherozoids) are flagellated and require water to swim to the female gametes (archegonia) for fertilization.
Therefore,water is essential for the fertilization process in these plants.

(D) The figure shows a fern,which is a characteristic member of the group Pteridophyta.
Ferns are vascular plants that reproduce via spores and have neither seeds nor flowers.
They possess a well-differentiated plant body into true roots,stems,and leaves.
Therefore,the correct group is Pteridophytes.

(A) The plant shown in the figure is a fern,which belongs to the group Pteridophyta.
In Pteridophytes,the main plant body is a sporophyte,which is differentiated into true root,stem,and leaves.
The sporophyte is independent,photosynthetic,and represents the dominant phase in the life cycle.
The gametophyte (prothallus) is small,inconspicuous,and multicellular,but it is not the dominant phase.
Therefore,the correct answer is the sporophyte.

(A) The plant shown in the figure is $Selaginella$.
$Selaginella$ is a pteridophyte that exhibits heterospory,meaning it produces two different types of spores: microspores and megaspores.
Therefore,the correct option is $A$.

(D) The figure shows a plant with a jointed stem,whorls of leaves at the nodes,and a terminal strobilus or cone. This morphology is characteristic of the genus $Equisetum$,which belongs to the class $Sphenopsida$ of the division $Pteridophyta$.

(C) The plant shown in the figure is Equisetum,which belongs to the group Pteridophytes.
In Pteridophytes,the main plant body is a sporophyte $(2n)$,which is differentiated into true root,stem,and leaves.
The gametophyte $(n)$ in Pteridophytes is small,inconspicuous,and usually short-lived,often called prothallus.
Therefore,the correct option is $(C)$ Gametophyte.

(B) The plant shown in the figure is Equisetum,which belongs to the class Sphenopsida of Pteridophytes.
Equisetum is a homosporous plant,meaning it produces spores of only one kind.
Therefore,the correct option is $(B)$.

(C) In Pteridophytes,reproduction occurs through the formation of spores. Most Pteridophytes are homosporous (producing one type of spore),while some are heterosporous (producing two types of spores: microspores and megaspores). Antheridium is a male sex organ involved in sexual reproduction,not asexual reproduction. Microsporangium is a structure that produces microspores,which is part of the heterosporous life cycle. However,among the given options,'Antheridium' is the most distinct as it is a reproductive organ for sexual reproduction,whereas the others relate to spore production types or structures.

(A) The process of seed development is considered an evolutionary precursor to the seed habit in plants.
$1$. Heterospory is the production of two different types of spores (microspores and megaspores) by the plant.
$2$. In heterosporous plants,the megaspore is retained within the parent sporophyte for variable periods.
$3$. The development of the zygote into young embryos takes place within the female gametophytes retained on the parent sporophytes.
$4$. This event is a precursor to the seed habit considered an important step in evolution,which is found in plants like $Selaginella$ and $Salvinia$.

(C) fernery is a specialized garden or a section of a botanical garden dedicated to the cultivation and display of ferns.
Ferns belong to the group of plants known as Pteridophytes.
Therefore,a fernery is essentially the cultivation of Pteridophytes.

(D) : In the majority of pteridophytes,all spores are of similar kinds; such plants are called homosporous. Genera like $Selaginella$ and $Salvinia$,which produce two kinds of spores,macro (large) and micro (small) spores,are known as heterosporous. The megaspores and microspores germinate and give rise to female and male gametophytes,respectively. The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos takes place within the female gametophytes. This event is a precursor to the seed habit,which is considered an important step in evolution.

(D) : In bryophytes,the dominant phase of the life cycle is the gametophytic plant body.
In contrast,vascular plants (pteridophytes,gymnosperms,and angiosperms) have a sporophytic plant body as the dominant phase of their life cycle.
Consequently,the gametophyte in vascular plants is highly reduced,smaller in size,and possesses smaller sex organs (antheridia and archegonia) compared to the relatively larger and more independent gametophytes of bryophytes.

(D) : In the majority of pteridophytes,all spores are of similar kinds; such plants are called homosporous.
Genera like $Selaginella$ and $Salvinia$,which produce two kinds of spores,macro (large) and micro (small) spores,are known as heterosporous.
The megaspores and microspores germinate and give rise to female and male gametophytes,respectively.
The female gametophytes in these plants are retained on the parent sporophytes for variable periods.
The development of the zygotes into young embryos takes place within the female gametophytes.
This event is a precursor to the seed habit,which is considered an important step in evolution.

(D) : Pteridophytes are known as vascular cryptogams ($Gk$ $kryptos$ = hidden + $gamos$ = wedded). They reproduce by spores rather than seeds. They are the first vascular land plants.
$Equisetum$ is a pteridophyte belonging to the Class $Sphenopsida$. All its vegetative parts possess vascular tissues ($i.e.$, hadrome equivalent to xylem and leptome equivalent to phloem) organized in definite groups of steles.

(A) : The differentiation of spores into microspores and megaspores,known as heterospory,is a crucial evolutionary step. The retention of the megaspore within the megasporangium on the parent sporophyte for development into the female gametophyte is considered an essential prerequisite for the formation of seeds,which is a characteristic feature of spermatophytes. This process allows the embryo to develop while being protected and nourished by the parent plant.

(D) The correct answer is $D$.
In pteridophytes,the sporophyte produces spores inside sporangia.
Most pteridophytes produce only one type of spore,known as homosporous (e.g.,$Equisetum$,$Adiantum$,$Dryopteris$).
However,some genera like $Salvinia$,$Selaginella$,$Azolla$,$Marsilea$,and $Isoetes$ produce two different types of spores,known as heterosporous.
Therefore,$Salvinia$ is heterosporous.

(C) The phenomenon where male and female reproductive organs mature at different times is known as dichogamy. In the prothallus of vascular cryptogams (like ferns),the antherozoids and eggs mature at different times. This temporal separation ensures that the sperm from one prothallus fertilizes the egg of another,thereby preventing self-fertilization and promoting cross-fertilization.

(A) Coal deposits are formed from the remains of ancient plants that lived millions of years ago.
Specifically,large quantities of Pteridophytes (ferns and fern-allies) grew in swampy forests during the Carboniferous period.
When these plants died,they were buried under layers of sediment,and over millions of years,heat and pressure converted them into coal.
Therefore,Pteridophytes are the primary contributors to coal deposits.

(D) Pteridophytes are a diverse group of seedless vascular plants. Based on their morphological and evolutionary characteristics,they are classified into $4$ main classes:
$1$. Psilopsida (e.g.,Psilotum)
$2$. Lycopsida (e.g.,Selaginella,Lycopodium)
$3$. Sphenopsida (e.g.,Equisetum)
$4$. Pteropsida (e.g.,Dryopteris,Pteris,Adiantum)
Therefore,the correct answer is $4$.