Q31. Which class of bryophytes includes mosses?
[A] Hepaticae
[B] Anthocerotae
[C] Bryopsida
[D] Pteropsida
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Correct Answer: ([C] Bryopsida
Explanation: The class Bryopsida includes mosses. They are characterized by an elaborate sporophyte, which is more differentiated than that of liverworts and hornworts. Examples include Funaria, Polytrichum, and Sphagnum.
Q32. The leafy stage of a moss develops from the secondary protonema as a:
[A] Zygote
[B] Bud
[C] Spore
[D] Gemma
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Correct Answer: [B] Bud
Explanation: In mosses, the life cycle starts with a spore that germinates to form a filamentous protonema. The protonema develops into the leafy stage, which bears the sex organs, from lateral buds.
Q33. Which of the following bryophytes has economic importance as a source of peat?
[A] Riccia
[B] Marchantia
[C] Sphagnum
[D] Funaria
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Correct Answer: [C] Sphagnum
Explanation: Sphagnum, or peat moss, is economically important as it forms peat, which is used as fuel, as a packing material for trans-shipment of living material because of its water-holding capacity, and in horticulture to improve soil texture.
Q34. The sporophyte of a bryophyte is dependent on the gametophyte for:
[A] Only nutrition
[B] Only anchorage
[C] Both nutrition and anchorage
[D] Neither nutrition nor anchorage
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Correct Answer: [C] Both nutrition and anchorage
Explanation: In bryophytes, the sporophyte is attached to the photosynthetic gametophyte and derives its nutrition from it. It also relies on the gametophyte for anchorage to the substratum.
Q35. In pteridophytes, the spores germinate to give rise to an inconspicuous, small, multicellular, free-living, mostly photosynthetic thalloid gametophyte called a:
[A] Protonema
[B] Prothallus
[C] Sporangium
[D] Strobilus
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Correct Answer: [B] Prothallus
Explanation: In pteridophytes, the haploid spores germinate to form a small, heart-shaped, multicellular, free-living, and mostly photosynthetic gametophyte called a prothallus. The sex organs (antheridia and archegoni[A] develop on the prothallus.
Q36. The male sex organ in pteridophytes is called the:
[A] Archegonium
[B] Antheridium
[C] Ovule
[D] Pollen grain
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Correct Answer: [B] Antheridium
Explanation: The antheridium is the male sex organ in pteridophytes. It produces flagellated sperm that require water to swim to the archegonium for fertilization.
Q37. The female sex organ in pteridophytes is called the:
[A] Antheridium
[B] Ovule
[C] Archegonium
[D] Pollen grain
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Correct Answer: [C] Archegonium
Explanation: The archegonium is the female sex organ in pteridophytes. It is a flask-shaped structure that contains a single egg. Fertilization occurs when a sperm swims to the archegonium and fuses with the egg to form a zygote.
Q38. The development of the zygote into a young embryo takes place within the:
[A] Antheridium
[B] Prothallus
[C] Archegonium
[D] Sporangium
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Correct Answer: [C] Archegonium
Explanation: In pteridophytes, after fertilization, the zygote remains within the archegonium where it develops into a young embryo. The embryo then grows into a multicellular sporophyte.
Q39. In pteridophytes, the sporophyte bears sporangia that are subtended by leaf-like appendages called:
[A] Sori
[B] Indusium
[C] Sporophylls
[D] Prothallus
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Correct Answer: [C] Sporophylls
Explanation: In pteridophytes, the sporophyte bears sporangia (spore-producing structures). In some pteridophytes, these sporangia are borne on specialized leaf-like appendages called sporophylls.
Q40. In ferns, the sporangia are clustered in structures called:
[A] Sporophylls
[B] Prothallus
[C] Sori
[D] Rhizomes
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Correct Answer: [C] Sori
Explanation: In ferns, the sporangia are often clustered in groups called sori, which are usually located on the undersurface of the leaves. The sori may be protected by a covering called the indusium.