Mosses - 1
Related Keywords
1
Which stage is predominant in the life cycle of a moss?
Practice
A
The sporophyte stage
B
The gametophyte stage
C
The zygote stage
D
The capsule stage
✅ Show Answer
✔ Correct Answer:
B
(The gametophyte stage)
💡 Explanation
Moss: Dictionary meaning — a small non-vascular bryophyte that commonly grows in moist and shaded habitats.
Explanation — In mosses, the gametophyte is the predominant and photosynthetic stage of the life cycle. It is the main plant body and consists of two successive stages.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte is the dominant stage of the life cycle. It develops from spores and eventually produces the male and female sex organs.
Predominant stage: Dictionary meaning — the stage that is the main or most conspicuous phase in a life cycle.
Explanation — The gametophyte is the predominant stage in mosses because it is long-lived, photosynthetic and forms the main visible plant body.
Two stages: Dictionary meaning — two distinct phases occurring successively during development.
Explanation — The moss gametophyte develops through two stages: the initial protonema stage and the leafy gametophore stage.
Sporophyte: Dictionary meaning — the diploid generation that develops from the zygote and produces spores.
Explanation — The moss sporophyte is dependent on the gametophyte for nourishment and is not the predominant stage of the life cycle.
Given Statement - The predominant stage of the life cycle of a moss is the gametophyte, which consists of two stages.
Explanation — In mosses, the gametophyte is the predominant and photosynthetic stage of the life cycle. It is the main plant body and consists of two successive stages.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte is the dominant stage of the life cycle. It develops from spores and eventually produces the male and female sex organs.
Predominant stage: Dictionary meaning — the stage that is the main or most conspicuous phase in a life cycle.
Explanation — The gametophyte is the predominant stage in mosses because it is long-lived, photosynthetic and forms the main visible plant body.
Two stages: Dictionary meaning — two distinct phases occurring successively during development.
Explanation — The moss gametophyte develops through two stages: the initial protonema stage and the leafy gametophore stage.
Sporophyte: Dictionary meaning — the diploid generation that develops from the zygote and produces spores.
Explanation — The moss sporophyte is dependent on the gametophyte for nourishment and is not the predominant stage of the life cycle.
Given Statement - The predominant stage of the life cycle of a moss is the gametophyte, which consists of two stages.
🎯 Conclusion
The gametophyte is the predominant stage in the life cycle of a moss. It is the main, haploid and photosynthetic plant body and develops through two stages: the protonema stage and the leafy gametophore stage. The gametophyte eventually produces the sex organs and supports the dependent sporophyte.
2
What is the first stage of the gametophyte in the life cycle of a moss?
Practice
A
Sporophyte stage, which develops from the zygote
B
Protonema stage, which develops directly from a spore
C
Gametophore stage, which develops from the capsule
D
Capsule stage, which develops from the antheridium
✅ Show Answer
✔ Correct Answer:
B
(Protonema stage, which develops directly from a spore)
💡 Explanation
Protonema: Dictionary meaning — the early, usually filamentous stage of the moss gametophyte that develops from a spore.
Explanation — The protonema is the first stage of the moss gametophyte. It develops directly from a haploid spore after the spore germinates under suitable conditions.
Spore: Dictionary meaning — a reproductive cell capable of developing into a new organism without fusion with another cell.
Explanation — In mosses, haploid spores are produced by meiosis in the sporophyte. When a spore germinates, it develops directly into the protonema stage.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The protonema represents the first stage of the moss gametophyte. It later develops buds that give rise to the leafy gametophore.
Germination: Dictionary meaning — the process by which a spore begins to grow and develop into a new organism.
Explanation — After germination, a moss spore develops into the protonema, marking the beginning of the gametophytic phase.
Gametophore: Dictionary meaning — the leafy shoot that develops from the protonema and bears the sex organs in mosses.
Explanation — The gametophore is the second stage of the moss gametophyte and develops from buds formed on the protonema.
Given Statement - The first stage of the moss gametophyte is the protonema stage, which develops directly from a spore.
Explanation — The protonema is the first stage of the moss gametophyte. It develops directly from a haploid spore after the spore germinates under suitable conditions.
Spore: Dictionary meaning — a reproductive cell capable of developing into a new organism without fusion with another cell.
Explanation — In mosses, haploid spores are produced by meiosis in the sporophyte. When a spore germinates, it develops directly into the protonema stage.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The protonema represents the first stage of the moss gametophyte. It later develops buds that give rise to the leafy gametophore.
Germination: Dictionary meaning — the process by which a spore begins to grow and develop into a new organism.
Explanation — After germination, a moss spore develops into the protonema, marking the beginning of the gametophytic phase.
Gametophore: Dictionary meaning — the leafy shoot that develops from the protonema and bears the sex organs in mosses.
Explanation — The gametophore is the second stage of the moss gametophyte and develops from buds formed on the protonema.
Given Statement - The first stage of the moss gametophyte is the protonema stage, which develops directly from a spore.
🎯 Conclusion
The protonema is the first stage of the moss gametophyte. It develops directly from a haploid spore when the spore germinates under suitable conditions. The protonema is generally filamentous and later produces buds that develop into the leafy gametophore, the second stage of the moss gametophyte.
3
Which of the following correctly describes the protonema stage of a moss?
Practice
A
It is a creeping, green, branched and frequently filamentous stage
B
It is a dry, non-green and unbranched stage
C
It is a spherical, unicellular and non-photosynthetic stage
D
It is a woody, vascular and upright stage
✅ Show Answer
✔ Correct Answer:
A
(It is a creeping, green, branched and frequently filamentous stage)
💡 Explanation
Protonema: Dictionary meaning — the early, usually filamentous stage of the moss gametophyte that develops from a spore.
Explanation — The protonema is a creeping, green and branched structure that is frequently filamentous. It develops directly from a germinating moss spore.
Creeping: Dictionary meaning — growing or spreading horizontally along the surface of the substrate.
Explanation — The protonema generally grows along the surface rather than standing upright, allowing it to spread over the substrate.
Green: Dictionary meaning — having chlorophyll and capable of carrying out photosynthesis.
Explanation — The protonema is green because it contains chlorophyll and can prepare food through photosynthesis.
Branched: Dictionary meaning — having a main structure that divides into smaller branches.
Explanation — The protonema commonly develops branches, increasing its area of growth and helping it establish itself on the substrate.
Filamentous: Dictionary meaning — having a long, thin, thread-like form.
Explanation — The protonema is frequently filamentous, consisting of elongated, thread-like cells that form the early moss gametophyte.
Given Statement - The protonema is a creeping, green, branched and frequently filamentous stage of the moss gametophyte.
Explanation — The protonema is a creeping, green and branched structure that is frequently filamentous. It develops directly from a germinating moss spore.
Creeping: Dictionary meaning — growing or spreading horizontally along the surface of the substrate.
Explanation — The protonema generally grows along the surface rather than standing upright, allowing it to spread over the substrate.
Green: Dictionary meaning — having chlorophyll and capable of carrying out photosynthesis.
Explanation — The protonema is green because it contains chlorophyll and can prepare food through photosynthesis.
Branched: Dictionary meaning — having a main structure that divides into smaller branches.
Explanation — The protonema commonly develops branches, increasing its area of growth and helping it establish itself on the substrate.
Filamentous: Dictionary meaning — having a long, thin, thread-like form.
Explanation — The protonema is frequently filamentous, consisting of elongated, thread-like cells that form the early moss gametophyte.
Given Statement - The protonema is a creeping, green, branched and frequently filamentous stage of the moss gametophyte.
🎯 Conclusion
The protonema is the first stage of the moss gametophyte and develops from a germinating spore. It is typically green, creeping, branched and frequently filamentous. Because it contains chlorophyll, it can perform photosynthesis. The protonema later produces buds that develop into the leafy gametophore stage.
4
What is the second stage of the gametophyte in the life cycle of a moss?
Practice
A
The capsule stage, which develops from the sporophyte
B
The leafy stage, which develops from the secondary protonema as a lateral bud
C
The zygote stage, which develops from the antheridium
D
The spore stage, which develops from the archegonium
✅ Show Answer
✔ Correct Answer:
B
(The leafy stage, which develops from the secondary protonema as a lateral bud)
💡 Explanation
Leafy stage: Dictionary meaning — the second stage of the moss gametophyte, consisting of a leafy shoot that develops from the protonema.
Explanation — The leafy stage develops from the secondary protonema as a lateral bud. It forms the leafy gametophore, which becomes the main visible plant body of the moss.
Secondary protonema: Dictionary meaning — a protonemal structure that develops from the primary protonema and gives rise to leafy shoots.
Explanation — The secondary protonema produces lateral buds. These buds grow and develop into the leafy stage of the moss gametophyte.
Lateral bud: Dictionary meaning — a bud that develops from the side of a plant structure rather than from its terminal tip.
Explanation — In mosses, the leafy stage originates as a lateral bud on the secondary protonema and subsequently develops into a leafy gametophore.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — The leafy gametophore develops from the protonema and represents the second stage of the moss gametophyte. It eventually produces antheridia and archegonia.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte consists of the protonema stage followed by the leafy stage. The leafy stage is the more developed and conspicuous part of the gametophyte.
Given Statement - The second stage of the moss gametophyte is the leafy stage, which develops from the secondary protonema as a lateral bud.
Explanation — The leafy stage develops from the secondary protonema as a lateral bud. It forms the leafy gametophore, which becomes the main visible plant body of the moss.
Secondary protonema: Dictionary meaning — a protonemal structure that develops from the primary protonema and gives rise to leafy shoots.
Explanation — The secondary protonema produces lateral buds. These buds grow and develop into the leafy stage of the moss gametophyte.
Lateral bud: Dictionary meaning — a bud that develops from the side of a plant structure rather than from its terminal tip.
Explanation — In mosses, the leafy stage originates as a lateral bud on the secondary protonema and subsequently develops into a leafy gametophore.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — The leafy gametophore develops from the protonema and represents the second stage of the moss gametophyte. It eventually produces antheridia and archegonia.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte consists of the protonema stage followed by the leafy stage. The leafy stage is the more developed and conspicuous part of the gametophyte.
Given Statement - The second stage of the moss gametophyte is the leafy stage, which develops from the secondary protonema as a lateral bud.
🎯 Conclusion
The leafy stage is the second stage of the moss gametophyte. It develops from the secondary protonema as a lateral bud and grows into a leafy gametophore. This stage forms the familiar leafy moss plant and later produces the male and female sex organs required for sexual reproduction.
5
Which of the following correctly describes the leafy stage of a moss gametophyte?
Practice
A
It consists of upright, slender axes bearing spirally arranged leaves
B
It consists of underground roots bearing alternate flowers
C
It consists of a flat thallus with no leaf-like structures
D
It consists of a single spherical cell without any appendages
✅ Show Answer
✔ Correct Answer:
A
(It consists of upright, slender axes bearing spirally arranged leaves)
💡 Explanation
Leafy stage: Dictionary meaning — the second stage of the moss gametophyte that develops from the protonema and forms a leafy shoot.
Explanation — The leafy stage consists of upright, slender axes that bear numerous leaf-like structures arranged spirally around the axis.
Upright axis: Dictionary meaning — a vertical or erect main supporting structure of a plant body.
Explanation — The leafy moss gametophore has an upright, slender axis from which the leaf-like structures arise.
Slender: Dictionary meaning — thin and narrow in form.
Explanation — The main axis of the leafy moss gametophore is generally thin and elongated, supporting the spirally arranged leaves.
Spirally arranged leaves: Dictionary meaning — leaves positioned successively around an axis in a spiral pattern.
Explanation — The leaf-like structures of the moss gametophore are arranged spirally around the upright axis, giving the moss its characteristic leafy appearance.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — The gametophore develops from the protonema and consists of an upright axis with spirally arranged leaves. It eventually produces the reproductive structures.
Given Statement - The leafy stage of mosses consists of upright, slender axes bearing spirally arranged leaves.
Explanation — The leafy stage consists of upright, slender axes that bear numerous leaf-like structures arranged spirally around the axis.
Upright axis: Dictionary meaning — a vertical or erect main supporting structure of a plant body.
Explanation — The leafy moss gametophore has an upright, slender axis from which the leaf-like structures arise.
Slender: Dictionary meaning — thin and narrow in form.
Explanation — The main axis of the leafy moss gametophore is generally thin and elongated, supporting the spirally arranged leaves.
Spirally arranged leaves: Dictionary meaning — leaves positioned successively around an axis in a spiral pattern.
Explanation — The leaf-like structures of the moss gametophore are arranged spirally around the upright axis, giving the moss its characteristic leafy appearance.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — The gametophore develops from the protonema and consists of an upright axis with spirally arranged leaves. It eventually produces the reproductive structures.
Given Statement - The leafy stage of mosses consists of upright, slender axes bearing spirally arranged leaves.
🎯 Conclusion
The leafy stage is the developed, visible part of the moss gametophyte. It consists of slender, upright axes bearing numerous leaf-like structures arranged in a spiral pattern. This leafy gametophore performs photosynthesis and later bears the male and female sex organs involved in sexual reproduction.
6
How is the leafy stage of a moss attached to the soil?
Practice
A
By unicellular and unbranched roots
B
By multicellular and branched rhizoids
C
By true roots with vascular tissues
D
By underground stems called stolons
✅ Show Answer
✔ Correct Answer:
B
(By multicellular and branched rhizoids)
💡 Explanation
Rhizoids: Dictionary meaning — root-like structures that anchor non-vascular plants to the substrate.
Explanation — Mosses are attached to the soil by rhizoids rather than true roots. Their rhizoids are multicellular and branched and help anchor the leafy gametophyte to the substrate.
Multicellular: Dictionary meaning — consisting of many cells.
Explanation — The rhizoids of mosses are multicellular, meaning they are composed of multiple cells arranged together to form the anchoring structure.
Branched: Dictionary meaning — having a main structure that divides into smaller branches.
Explanation — Moss rhizoids are branched, which increases their contact with the soil and helps the plant remain firmly attached to the substrate.
Leafy stage: Dictionary meaning — the second stage of the moss gametophyte consisting of an upright leafy shoot.
Explanation — The leafy gametophore is attached to the soil through its multicellular, branched rhizoids. Mosses do not possess true roots.
True roots: Dictionary meaning — specialised underground plant organs containing vascular tissues and primarily involved in anchorage and absorption.
Explanation — Mosses lack true roots. Instead, they use rhizoids mainly for attachment to the substrate.
Given Statement - The leafy stage of mosses is attached to the soil through multicellular and branched rhizoids.
Explanation — Mosses are attached to the soil by rhizoids rather than true roots. Their rhizoids are multicellular and branched and help anchor the leafy gametophyte to the substrate.
Multicellular: Dictionary meaning — consisting of many cells.
Explanation — The rhizoids of mosses are multicellular, meaning they are composed of multiple cells arranged together to form the anchoring structure.
Branched: Dictionary meaning — having a main structure that divides into smaller branches.
Explanation — Moss rhizoids are branched, which increases their contact with the soil and helps the plant remain firmly attached to the substrate.
Leafy stage: Dictionary meaning — the second stage of the moss gametophyte consisting of an upright leafy shoot.
Explanation — The leafy gametophore is attached to the soil through its multicellular, branched rhizoids. Mosses do not possess true roots.
True roots: Dictionary meaning — specialised underground plant organs containing vascular tissues and primarily involved in anchorage and absorption.
Explanation — Mosses lack true roots. Instead, they use rhizoids mainly for attachment to the substrate.
Given Statement - The leafy stage of mosses is attached to the soil through multicellular and branched rhizoids.
🎯 Conclusion
The leafy stage of a moss is attached to the soil by multicellular and branched rhizoids. These root-like structures provide anchorage and help the moss remain firmly attached to the substrate. Unlike vascular plants, mosses do not have true roots, so rhizoids perform the important function of attachment.
7
Which stage of the moss gametophyte bears the sex organs?
Practice
A
The protonema stage
B
The leafy stage
C
The capsule stage
D
The spore stage
✅ Show Answer
✔ Correct Answer:
B
(The leafy stage)
💡 Explanation
Leafy stage: Dictionary meaning — the second stage of the moss gametophyte that develops from the protonema and forms a leafy shoot.
Explanation — The leafy stage of the moss gametophyte bears the male and female sex organs, namely antheridia and archegonia.
Sex organs: Dictionary meaning — reproductive structures that produce or contain the gametes involved in sexual reproduction.
Explanation — In mosses, the leafy gametophore bears the sex organs. The antheridia produce male gametes, while the archegonia contain the female gamete.
Antheridium: Dictionary meaning — the male sex organ that produces male gametes.
Explanation — The antheridium is borne on the leafy gametophyte and produces biflagellate antherozoids that participate in fertilisation.
Archegonium: Dictionary meaning — the female sex organ that produces and contains the egg.
Explanation — The archegonium is also borne on the leafy gametophyte and contains the female gamete, or egg, which fuses with the male gamete during fertilisation.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte is the predominant generation. Its leafy stage bears the reproductive organs and is therefore responsible for sexual reproduction.
Given Statement - The leafy stage of the moss gametophyte bears the sex organs.
Explanation — The leafy stage of the moss gametophyte bears the male and female sex organs, namely antheridia and archegonia.
Sex organs: Dictionary meaning — reproductive structures that produce or contain the gametes involved in sexual reproduction.
Explanation — In mosses, the leafy gametophore bears the sex organs. The antheridia produce male gametes, while the archegonia contain the female gamete.
Antheridium: Dictionary meaning — the male sex organ that produces male gametes.
Explanation — The antheridium is borne on the leafy gametophyte and produces biflagellate antherozoids that participate in fertilisation.
Archegonium: Dictionary meaning — the female sex organ that produces and contains the egg.
Explanation — The archegonium is also borne on the leafy gametophyte and contains the female gamete, or egg, which fuses with the male gamete during fertilisation.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The moss gametophyte is the predominant generation. Its leafy stage bears the reproductive organs and is therefore responsible for sexual reproduction.
Given Statement - The leafy stage of the moss gametophyte bears the sex organs.
🎯 Conclusion
The leafy stage, or gametophore, is the reproductive stage of the moss gametophyte. It bears the male sex organs called antheridia and the female sex organs called archegonia. These organs produce the gametes required for sexual reproduction, making the leafy stage essential for the continuation of the moss life cycle.
8
How does vegetative reproduction occur in mosses?
Practice
A
By fragmentation and budding in the secondary protonema
B
By formation of flowers and fruits
C
By fusion of antherozoids and eggs
D
By formation of seeds inside the capsule
✅ Show Answer
✔ Correct Answer:
A
(By fragmentation and budding in the secondary protonema)
💡 Explanation
Vegetative reproduction: Dictionary meaning — a type of asexual reproduction in which new individuals develop from vegetative parts of the parent plant without the formation or fusion of gametes.
Explanation — In mosses, vegetative reproduction occurs by fragmentation and by budding in the secondary protonema. These processes produce new gametophytic individuals without fertilisation.
Fragmentation: Dictionary meaning — a method of reproduction in which a part of the parent body separates and develops into a new individual.
Explanation — In mosses, fragments of the plant body can separate and grow into new plants under suitable conditions.
Budding: Dictionary meaning — a form of asexual reproduction in which a new individual develops as a small outgrowth or bud from the parent structure.
Explanation — In mosses, buds develop on the secondary protonema and grow into new leafy gametophores.
Secondary protonema: Dictionary meaning — a protonemal structure that develops from the primary protonema and gives rise to leafy shoots.
Explanation — The secondary protonema can produce buds that develop into new leafy gametophores, providing an important method of vegetative reproduction.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — Buds formed on the secondary protonema can develop into leafy gametophores, which become the mature gametophytic plants.
Given Statement - Vegetative reproduction in mosses occurs by fragmentation and budding in the secondary protonema.
Explanation — In mosses, vegetative reproduction occurs by fragmentation and by budding in the secondary protonema. These processes produce new gametophytic individuals without fertilisation.
Fragmentation: Dictionary meaning — a method of reproduction in which a part of the parent body separates and develops into a new individual.
Explanation — In mosses, fragments of the plant body can separate and grow into new plants under suitable conditions.
Budding: Dictionary meaning — a form of asexual reproduction in which a new individual develops as a small outgrowth or bud from the parent structure.
Explanation — In mosses, buds develop on the secondary protonema and grow into new leafy gametophores.
Secondary protonema: Dictionary meaning — a protonemal structure that develops from the primary protonema and gives rise to leafy shoots.
Explanation — The secondary protonema can produce buds that develop into new leafy gametophores, providing an important method of vegetative reproduction.
Gametophore: Dictionary meaning — the leafy shoot of a moss gametophyte that bears the sex organs.
Explanation — Buds formed on the secondary protonema can develop into leafy gametophores, which become the mature gametophytic plants.
Given Statement - Vegetative reproduction in mosses occurs by fragmentation and budding in the secondary protonema.
🎯 Conclusion
Mosses can reproduce vegetatively without sexual reproduction or fertilisation. This occurs mainly through fragmentation and budding in the secondary protonema. Fragments can develop into new plants, while buds formed on the secondary protonema grow into leafy gametophores. Thus, vegetative reproduction helps mosses multiply efficiently under suitable conditions.
9
Where are the sex organs produced in mosses during sexual reproduction?
Practice
A
At the base of the rhizoids
B
At the apex of the leafy shoots
C
Inside the capsule of the sporophyte
D
On the surface of the protonema
✅ Show Answer
✔ Correct Answer:
B
(At the apex of the leafy shoots)
💡 Explanation
Sexual reproduction: Dictionary meaning — reproduction involving the formation and fusion of male and female gametes.
Explanation — In mosses, sexual reproduction involves the formation of the male sex organ, antheridium, and the female sex organ, archegonium, on the leafy gametophyte.
Antheridium: Dictionary meaning — the male reproductive organ that produces male gametes.
Explanation — The antheridia are produced at the apex of the leafy shoots and produce biflagellate antherozoids that participate in fertilisation.
Archegonium: Dictionary meaning — the female reproductive organ that produces and contains the egg.
Explanation — The archegonia are also produced at the apex of the leafy shoots. Each archegonium contains a single egg that can fuse with an antherozoid during fertilisation.
Leafy shoot: Dictionary meaning — the upright leafy gametophore that forms the second stage of the moss gametophyte.
Explanation — The leafy shoot is the reproductive part of the moss gametophyte. Its apex bears the sex organs involved in sexual reproduction.
Apex: Dictionary meaning — the tip or uppermost part of a structure.
Explanation — The sex organs of mosses are produced at the apex, or tip, of the leafy shoots, where sexual reproduction takes place.
Given Statement - In sexual reproduction, the sex organs antheridia and archegonia are produced at the apex of the leafy shoots.
Explanation — In mosses, sexual reproduction involves the formation of the male sex organ, antheridium, and the female sex organ, archegonium, on the leafy gametophyte.
Antheridium: Dictionary meaning — the male reproductive organ that produces male gametes.
Explanation — The antheridia are produced at the apex of the leafy shoots and produce biflagellate antherozoids that participate in fertilisation.
Archegonium: Dictionary meaning — the female reproductive organ that produces and contains the egg.
Explanation — The archegonia are also produced at the apex of the leafy shoots. Each archegonium contains a single egg that can fuse with an antherozoid during fertilisation.
Leafy shoot: Dictionary meaning — the upright leafy gametophore that forms the second stage of the moss gametophyte.
Explanation — The leafy shoot is the reproductive part of the moss gametophyte. Its apex bears the sex organs involved in sexual reproduction.
Apex: Dictionary meaning — the tip or uppermost part of a structure.
Explanation — The sex organs of mosses are produced at the apex, or tip, of the leafy shoots, where sexual reproduction takes place.
Given Statement - In sexual reproduction, the sex organs antheridia and archegonia are produced at the apex of the leafy shoots.
🎯 Conclusion
During sexual reproduction in mosses, the leafy gametophyte produces the male sex organs called antheridia and the female sex organs called archegonia. These reproductive structures are located at the apex of the leafy shoots. The antheridia produce male gametes, while the archegonia contain the eggs required for fertilisation.
10
What does the zygote develop into after fertilisation in mosses?
Practice
A
A protonema consisting of rhizoids and leaves
B
A sporophyte consisting of a foot, seta and capsule
C
A gametophyte consisting of antheridia and archegonia
D
A gemma consisting of a foot, seta and capsule
✅ Show Answer
✔ Correct Answer:
B
(A sporophyte consisting of a foot, seta and capsule)
💡 Explanation
Zygote: Dictionary meaning — the diploid cell formed by the fusion of male and female gametes during fertilisation.
Explanation — In mosses, the zygote remains attached to the female gametophyte and develops through repeated cell divisions into a multicellular diploid sporophyte.
Sporophyte: Dictionary meaning — the diploid generation of a plant that develops from the zygote and produces spores.
Explanation — After fertilisation, the moss zygote develops into the sporophyte. The sporophyte is differentiated into three main parts: foot, seta and capsule.
Foot: Dictionary meaning — the basal part of the sporophyte that is embedded in or attached to the gametophyte.
Explanation — The foot anchors the sporophyte to the gametophyte and absorbs nourishment from the gametophytic tissue.
Seta: Dictionary meaning — the stalk-like part of the sporophyte that supports the capsule.
Explanation — The seta connects the foot to the capsule and elevates the capsule, helping in the effective dispersal of spores.
Capsule: Dictionary meaning — the spore-producing part of the sporophyte.
Explanation — The capsule contains spore-producing cells. These cells undergo meiosis to form haploid spores, which are eventually released and germinate to produce new gametophytes.
Given Statement - After fertilisation, the zygote develops into a sporophyte consisting of a foot, seta and capsule.
Explanation — In mosses, the zygote remains attached to the female gametophyte and develops through repeated cell divisions into a multicellular diploid sporophyte.
Sporophyte: Dictionary meaning — the diploid generation of a plant that develops from the zygote and produces spores.
Explanation — After fertilisation, the moss zygote develops into the sporophyte. The sporophyte is differentiated into three main parts: foot, seta and capsule.
Foot: Dictionary meaning — the basal part of the sporophyte that is embedded in or attached to the gametophyte.
Explanation — The foot anchors the sporophyte to the gametophyte and absorbs nourishment from the gametophytic tissue.
Seta: Dictionary meaning — the stalk-like part of the sporophyte that supports the capsule.
Explanation — The seta connects the foot to the capsule and elevates the capsule, helping in the effective dispersal of spores.
Capsule: Dictionary meaning — the spore-producing part of the sporophyte.
Explanation — The capsule contains spore-producing cells. These cells undergo meiosis to form haploid spores, which are eventually released and germinate to produce new gametophytes.
Given Statement - After fertilisation, the zygote develops into a sporophyte consisting of a foot, seta and capsule.
🎯 Conclusion
After fertilisation, the diploid zygote of a moss develops into a multicellular sporophyte. The sporophyte is differentiated into three main parts: the foot, seta and capsule. The foot remains attached to the gametophyte and provides nourishment, the seta supports the capsule, and the capsule produces spores that continue the life cycle.
11
How does the sporophyte of mosses compare with that of liverworts?
Practice
A
The sporophyte of mosses is simpler than that of liverworts
B
The sporophyte of mosses is more elaborate than that of liverworts
C
Both have exactly the same sporophyte structure
D
Liverworts do not produce a sporophyte
✅ Show Answer
✔ Correct Answer:
B
(The sporophyte of mosses is more elaborate than that of liverworts)
💡 Explanation
Sporophyte: Dictionary meaning — the diploid generation of a plant that develops from the zygote and produces spores.
Explanation — Both mosses and liverworts produce sporophytes after fertilisation. However, the sporophyte of mosses is generally more elaborate and structurally differentiated than that of liverworts.
Mosses: Dictionary meaning — non-vascular bryophytes with a predominant gametophyte and a dependent sporophyte.
Explanation — The moss sporophyte is differentiated into a foot, seta and capsule and has a relatively complex structure involved in the production and dispersal of spores.
Liverworts: Dictionary meaning — bryophytes that may have a thalloid or leafy gametophyte and a dependent sporophyte.
Explanation — The liverwort sporophyte is also differentiated into a foot, seta and capsule, but its structure is generally less elaborate than the sporophyte of mosses.
Elaborate: Dictionary meaning — more complex, detailed or highly developed in structure.
Explanation — The moss sporophyte has greater structural differentiation and specialised features associated with spore production and dispersal, making it more elaborate than that of liverworts.
Given Statement - The sporophyte in mosses is more elaborate than that in liverworts.
Explanation — Both mosses and liverworts produce sporophytes after fertilisation. However, the sporophyte of mosses is generally more elaborate and structurally differentiated than that of liverworts.
Mosses: Dictionary meaning — non-vascular bryophytes with a predominant gametophyte and a dependent sporophyte.
Explanation — The moss sporophyte is differentiated into a foot, seta and capsule and has a relatively complex structure involved in the production and dispersal of spores.
Liverworts: Dictionary meaning — bryophytes that may have a thalloid or leafy gametophyte and a dependent sporophyte.
Explanation — The liverwort sporophyte is also differentiated into a foot, seta and capsule, but its structure is generally less elaborate than the sporophyte of mosses.
Elaborate: Dictionary meaning — more complex, detailed or highly developed in structure.
Explanation — The moss sporophyte has greater structural differentiation and specialised features associated with spore production and dispersal, making it more elaborate than that of liverworts.
Given Statement - The sporophyte in mosses is more elaborate than that in liverworts.
🎯 Conclusion
The sporophyte of mosses is more elaborate and structurally complex than that of liverworts. Although both groups produce a sporophyte with a foot, seta and capsule, moss sporophytes show greater differentiation and specialised structures for spore production and dispersal. This makes the moss sporophyte comparatively more developed.
12
What does the capsule of a moss sporophyte contain?
Practice
A
Gametes
B
Spores
C
Gemmae
D
Rhizoids
✅ Show Answer
✔ Correct Answer:
B
(Spores)
💡 Explanation
Capsule: Dictionary meaning — the spore-producing part of the sporophyte in bryophytes.
Explanation — In mosses, the capsule is the terminal part of the sporophyte and contains spores produced through meiosis.
Spores: Dictionary meaning — reproductive cells that can develop into new individuals without fusion with another cell.
Explanation — The spores inside the moss capsule are haploid and are produced by reduction division or meiosis. After release, they germinate to form the protonema stage of the gametophyte.
Sporophyte: Dictionary meaning — the diploid generation that develops from the zygote and produces spores.
Explanation — The moss sporophyte consists of a foot, seta and capsule. The capsule is responsible for producing and containing the spores.
Meiosis: Dictionary meaning — a specialised type of cell division that reduces the chromosome number by half.
Explanation — Cells within the capsule undergo meiosis to produce haploid spores, which later continue the moss life cycle by developing into gametophytes.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — When the haploid spores are released from the capsule and germinate, they develop into the gametophyte, beginning with the protonema stage.
Given Statement - The capsule of the moss sporophyte contains spores.
Explanation — In mosses, the capsule is the terminal part of the sporophyte and contains spores produced through meiosis.
Spores: Dictionary meaning — reproductive cells that can develop into new individuals without fusion with another cell.
Explanation — The spores inside the moss capsule are haploid and are produced by reduction division or meiosis. After release, they germinate to form the protonema stage of the gametophyte.
Sporophyte: Dictionary meaning — the diploid generation that develops from the zygote and produces spores.
Explanation — The moss sporophyte consists of a foot, seta and capsule. The capsule is responsible for producing and containing the spores.
Meiosis: Dictionary meaning — a specialised type of cell division that reduces the chromosome number by half.
Explanation — Cells within the capsule undergo meiosis to produce haploid spores, which later continue the moss life cycle by developing into gametophytes.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — When the haploid spores are released from the capsule and germinate, they develop into the gametophyte, beginning with the protonema stage.
Given Statement - The capsule of the moss sporophyte contains spores.
🎯 Conclusion
The capsule is the spore-producing part of the moss sporophyte and contains haploid spores. These spores are formed through meiosis and are later released from the capsule. Under suitable conditions, they germinate to form the protonema, which develops into the leafy gametophyte and continues the moss life cycle.
13
How are spores formed in the moss sporophyte?
Practice
A
Spores are formed by fertilisation
B
Spores are formed after meiosis
C
Spores are formed by fusion of gametes
D
Spores are formed by budding
✅ Show Answer
✔ Correct Answer:
B
(Spores are formed after meiosis)
💡 Explanation
Spores: Dictionary meaning — reproductive cells that can develop into new individuals without fusion with another cell.
Explanation — In mosses, spores are produced in the capsule of the sporophyte after the cells undergo meiosis. The resulting spores are haploid and later germinate to form the gametophyte.
Meiosis: Dictionary meaning — a specialised type of cell division that reduces the chromosome number by half.
Explanation — Meiosis occurs in the spore-producing cells of the moss capsule. It reduces the chromosome number from diploid to haploid and results in the formation of haploid spores.
Capsule: Dictionary meaning — the spore-producing part of the bryophyte sporophyte.
Explanation — The capsule of the moss sporophyte contains the cells that undergo meiosis and subsequently produces haploid spores.
Haploid: Dictionary meaning — having a single set of chromosomes, represented as n.
Explanation — The spores produced after meiosis are haploid. When they germinate, they develop into the haploid gametophyte generation.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The haploid spores formed after meiosis germinate to produce the protonema, which develops into the leafy gametophyte.
Given Statement - Spores are formed after meiosis.
Explanation — In mosses, spores are produced in the capsule of the sporophyte after the cells undergo meiosis. The resulting spores are haploid and later germinate to form the gametophyte.
Meiosis: Dictionary meaning — a specialised type of cell division that reduces the chromosome number by half.
Explanation — Meiosis occurs in the spore-producing cells of the moss capsule. It reduces the chromosome number from diploid to haploid and results in the formation of haploid spores.
Capsule: Dictionary meaning — the spore-producing part of the bryophyte sporophyte.
Explanation — The capsule of the moss sporophyte contains the cells that undergo meiosis and subsequently produces haploid spores.
Haploid: Dictionary meaning — having a single set of chromosomes, represented as n.
Explanation — The spores produced after meiosis are haploid. When they germinate, they develop into the haploid gametophyte generation.
Gametophyte: Dictionary meaning — the haploid generation of a plant that produces gametes.
Explanation — The haploid spores formed after meiosis germinate to produce the protonema, which develops into the leafy gametophyte.
Given Statement - Spores are formed after meiosis.
🎯 Conclusion
In mosses, spores are formed in the capsule of the sporophyte after meiosis. During meiosis, diploid spore-producing cells undergo reduction division and form haploid spores. These spores are later released and germinate to produce the protonema, which develops into the leafy gametophyte.
14
Which statement correctly describes spore dispersal in mosses?
Practice
A
Mosses have no specialised mechanism for spore dispersal
B
Mosses have an elaborate mechanism of spore dispersal
C
Mosses disperse spores only through water
D
Mosses disperse spores only through animals
✅ Show Answer
✔ Correct Answer:
B
(Mosses have an elaborate mechanism of spore dispersal)
💡 Explanation
Mosses: Dictionary meaning — small non-vascular plants belonging to the bryophyte group.
Explanation — Mosses have a well-developed and elaborate mechanism for dispersing their spores. Specialised structures in the capsule help release the spores efficiently into the surrounding environment.
Spore dispersal: Dictionary meaning — the process by which spores are released and distributed away from the parent plant.
Explanation — Effective spore dispersal allows mosses to spread to new suitable habitats. The moss capsule contains specialised structures that assist in controlled spore release.
Capsule: Dictionary meaning — the spore-producing part of the moss sporophyte.
Explanation — The capsule contains the spores and specialised structures involved in their release and dispersal. Its structure helps ensure that spores are dispersed under suitable conditions.
Elaborate mechanism: Dictionary meaning — a complex and well-developed system involving specialised structures or processes.
Explanation — In mosses, structures associated with the capsule, such as the peristome teeth, help regulate the release of spores and contribute to an efficient dispersal mechanism.
Peristome: Dictionary meaning — a ring of specialised teeth around the opening of the capsule in many mosses that helps regulate spore release.
Explanation — The peristome teeth respond to changes in humidity and help release spores gradually, improving their chances of dispersal to suitable locations.
Given Statement - The mosses have an elaborate mechanism of spore dispersal.
Explanation — Mosses have a well-developed and elaborate mechanism for dispersing their spores. Specialised structures in the capsule help release the spores efficiently into the surrounding environment.
Spore dispersal: Dictionary meaning — the process by which spores are released and distributed away from the parent plant.
Explanation — Effective spore dispersal allows mosses to spread to new suitable habitats. The moss capsule contains specialised structures that assist in controlled spore release.
Capsule: Dictionary meaning — the spore-producing part of the moss sporophyte.
Explanation — The capsule contains the spores and specialised structures involved in their release and dispersal. Its structure helps ensure that spores are dispersed under suitable conditions.
Elaborate mechanism: Dictionary meaning — a complex and well-developed system involving specialised structures or processes.
Explanation — In mosses, structures associated with the capsule, such as the peristome teeth, help regulate the release of spores and contribute to an efficient dispersal mechanism.
Peristome: Dictionary meaning — a ring of specialised teeth around the opening of the capsule in many mosses that helps regulate spore release.
Explanation — The peristome teeth respond to changes in humidity and help release spores gradually, improving their chances of dispersal to suitable locations.
Given Statement - The mosses have an elaborate mechanism of spore dispersal.
🎯 Conclusion
Mosses possess an elaborate mechanism for spore dispersal that helps distribute spores effectively. The capsule contains specialised structures, particularly the peristome teeth in many mosses, which regulate the gradual release of spores. This controlled dispersal increases the likelihood that spores will reach suitable places where they can germinate and develop into new gametophytes.
15
Which of the following includes common examples of mosses?
Practice
A
Marchantia, Riccia and Anthoceros
B
Funaria, Polytrichum and Sphagnum
C
Chlamydomonas, Spirogyra and Volvox
D
Ectocarpus, Sargassum and Fucus
✅ Show Answer
✔ Correct Answer:
B
(Funaria, Polytrichum and Sphagnum)
💡 Explanation
Mosses: Dictionary meaning — non-vascular bryophytes that commonly grow in moist and shaded habitats.
Explanation — Funaria, Polytrichum and Sphagnum are common examples of mosses. They exhibit the characteristic moss life cycle in which the gametophyte is the predominant stage.
Funaria: Dictionary meaning — a common genus of moss belonging to the bryophytes.
Explanation — Funaria is a widely studied moss and is commonly used as an example to understand the structure and life cycle of mosses.
Polytrichum: Dictionary meaning — a genus of mosses belonging to the family Polytrichaceae.
Explanation — Polytrichum is a common moss with an upright leafy gametophyte and a distinct sporophyte.
Sphagnum: Dictionary meaning — a genus of moss commonly known as peat moss.
Explanation — Sphagnum is an important moss that can form peat and has a high capacity to hold water. It is also ecologically significant in wetland habitats.
Given Statement - Common examples of mosses are Funaria, Polytrichum and Sphagnum.
Explanation — Funaria, Polytrichum and Sphagnum are common examples of mosses. They exhibit the characteristic moss life cycle in which the gametophyte is the predominant stage.
Funaria: Dictionary meaning — a common genus of moss belonging to the bryophytes.
Explanation — Funaria is a widely studied moss and is commonly used as an example to understand the structure and life cycle of mosses.
Polytrichum: Dictionary meaning — a genus of mosses belonging to the family Polytrichaceae.
Explanation — Polytrichum is a common moss with an upright leafy gametophyte and a distinct sporophyte.
Sphagnum: Dictionary meaning — a genus of moss commonly known as peat moss.
Explanation — Sphagnum is an important moss that can form peat and has a high capacity to hold water. It is also ecologically significant in wetland habitats.
Given Statement - Common examples of mosses are Funaria, Polytrichum and Sphagnum.
🎯 Conclusion
Funaria, Polytrichum and Sphagnum are common examples of mosses. These plants belong to the bryophytes and have a dominant gametophyte generation. Funaria and Polytrichum are commonly studied mosses, while Sphagnum is well known as peat moss because of its ability to retain large amounts of water and contribute to peat formation.