PLANT KINGDOM MCQs for NEET UG BIOLOGY — Hard, Page 2

31 Hard

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Zooidogamy is found in

View answer and explanation

Correct option: C

Cycas

Option C (Cycas) is correct because zooidogamy, the fertilization of an egg by a motile sperm, is a characteristic feature of Cycas.

Solution approach

Correct Answer + Core Reason: Cycas. Zooidogamy, the fertilization of an egg by a motile sperm, is found in Cycas.

Step-by-Step Solution:

Step 1: Define zooidogamy.

Step 2: Recall the plants exhibiting zooidogamy.

Step 3: Zooidogamy is a characteristic feature of Cycas.

Why other options are wrong:
- Option A: Cedrus (a type of pine) exhibits siphonogamy, where pollen tube carries the non-motile male gametes to the egg cell.
- Option B: Pinus also exhibits siphonogamy, not zooidogamy.
- Option D: While Cycas exhibits zooidogamy, Pinus does not, making this option incorrect.

Key Concepts:
- Zooidogamy
- Cycas
- Gymnosperm reproduction

Memory Aids:
- Remember *Cycas* and *zooidogamy* together.

Quick Tips:
- Distinguish between zooidogamy and siphonogamy.

32 Hard

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Assertion: Gametophyte is dominant in diplontic life cycle.
Reason: In diplontic life cycle, free living sporophyte is absent.

View answer and explanation

Correct option: D

If both the assertion and reason are incorrect.

Option D is correct because both the assertion and the reason are incorrect. Gametophyte is dominant in haplontic life cycle, and sporophyte is absent in haplontic life cycle.

Solution approach

Correct Answer + Core Reason: If both the assertion and reason are incorrect. The assertion and reason are both factually wrong regarding life cycles.

Step-by-Step Solution:

Step 1: Analyze the assertion: Gametophyte is dominant in haplontic life cycle, not diplontic.

Step 2: Analyze the reason: In diplontic life cycle, the sporophyte is the dominant, independent, photosynthetic phase.

Step 3: Combine the analyses: Both statements are incorrect.

Step 4: Conclusion: Since both assertion and reason are incorrect, the correct answer is D.

Why other options are wrong:
- Option A: Incorrect because both assertion and reason are not correct.
- Option B: Incorrect because both assertion and reason are not correct.
- Option C: Incorrect because the assertion is not correct.
- Option D: Correct because both the assertion and reason are incorrect.

Key Concepts:
- Life cycles in plants (Haplontic, Diplontic, Haplodiplontic)
- Gametophyte and Sporophyte generations

Memory Aids:
- Diplontic: "Di" means two, referring to the diploid sporophyte being the dominant phase.
- Haplontic: "Hap" means single, referring to the haploid gametophyte being the dominant phase.

Quick Tips:
- Remember the dominant phase in each life cycle type.

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[A]: Flagella found in green algae are of tinsel type.

[R]: Flagella in algae are whiplash type.

View answer and explanation

Correct option: D

Both A and R are false

Option D (Both A and R are false) is correct because flagella in green algae are of the whiplash type, and the assertion states they are tinsel type, while the reason states they are whiplash type (which is correct, but makes the reason contradictory).

Solution approach

Correct Answer + Core Reason: Both A and R are false. Flagella in green algae are whiplash type, not tinsel type.

Step-by-Step Solution:

Step 1: Define tinsel and whiplash flagella.

Step 2: Tinsel flagella have lateral filaments along the flagellar shaft.

Step 3: Whiplash flagella are smooth.

Step 4: Flagella in green algae are typically whiplash type.

Step 5: Therefore, both the assertion (A) and the reason (R) are false.

Why other options are wrong:
- Option A: Both A and R are true and R is the correct explanation of A: Both A and R are false.
- Option B: Both A and R are true and R is not the correct explanation of A: Both A and R are false.
- Option C: A is true but R is false: Both A and R are false.

Key Concepts:
- Flagellar types: tinsel and whiplash
- Flagella in algae

Memory Aids:
- Whiplash = Smooth
- Tinsel = Filaments

Quick Tips:
- Remember the difference between tinsel and whiplash flagella.

34 Hard

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Pollen sac in Cycas is called

View answer and explanation

Correct option: D

Microsporangium

Option D (Microsporangium) is correct because the pollen sac in Cycas, where microspores develop into pollen grains, is called a microsporangium.

Solution approach

Correct Answer + Core Reason: Microsporangium. Pollen sac in Cycas is called microsporangium.

Step-by-Step Solution:

Step 1: Define pollen sac.

Step 2: Understand the process of microsporogenesis in Cycas.

Step 3: Identify the structure that contains the developing pollen grains.

Step 4: Conclude that the pollen sac is called microsporangium.

Why other options are wrong:
- Option A: Megasporophyll is the leaf-like structure bearing megasporangia.
- Option B: Megasporangium contains the megaspore mother cell.
- Option C: Microsporophyll is the leaf-like structure bearing microsporangia.

Key Concepts:
- Microsporogenesis
- Microsporangium
- Cycas reproduction

Memory Aids:
- Micro = Pollen

Quick Tips:
- Remember the difference between micro- and mega- structures in plant reproduction.

35 Hard

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Phloem tissue of angiosperms differs from that of gymnosperms in having

View answer and explanation

Correct option: A

Companion cells

Option A (Companion cells) is correct because companion cells are present in the phloem of angiosperms but absent in gymnosperms.

Solution approach

Correct Answer + Core Reason: Companion cells. These are associated with sieve tubes in angiosperms but are absent in gymnosperms.

Step-by-Step Solution:

Step 1: Recall the structure of phloem tissue in angiosperms and gymnosperms.

Step 2: Phloem tissue consists of sieve elements and companion cells (in angiosperms) or albuminous cells (in gymnosperms).

Step 3: Sieve cells are present in both angiosperms and gymnosperms.

Step 4: Sieve tubes are formed by sieve tube elements in angiosperms. Gymnosperms have sieve cells but not sieve tubes.

Step 5: Companion cells are associated with sieve tubes in angiosperms and provide metabolic support.

Step 6: Gymnosperms lack companion cells; instead, they have albuminous cells associated with sieve cells.

Why other options are wrong:
- Option B: Sieve cells are present in both angiosperms and gymnosperms.
- Option C: Sieve tubes are present in angiosperms, not absent.
- Option D: Only companion cells are unique to angiosperms compared to gymnosperms.

Key Concepts:
- Phloem tissue
- Angiosperms
- Gymnosperms
- Sieve cells
- Sieve tubes
- Companion cells
- Albuminous cells

Memory Aids:
- Remember that companion cells are found in angiosperms, while albuminous cells are found in gymnosperms.

Quick Tips:
- Compare the structures of vascular tissues in different plant groups.

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Which of these is mismatched?

View answer and explanation

Correct option: D

Bryon - Liverworts

Option D (Bryon - Liverworts) is correct because "Bryon" refers to mosses, not liverworts. Liverworts belong to the group Hepaticae.

Solution approach

Correct Answer + Core Reason: Bryon - Liverworts. Bryon refers to mosses, not liverworts.

Step-by-Step Solution:

Step 1: Understand the question: The question asks to identify the mismatched pair.

Step 2: Evaluate each option:
- Phaneros - Visible: Phaneros means visible, so this is correct.
- Kryptos - Concealed: Kryptos means concealed, so this is correct.
- Gymno - Naked: Gymno means naked, so this is correct.
- Bryon - Liverworts: Bryon refers to mosses, while liverworts belong to Hepaticae.

Step 3: Conclusion: Therefore, Bryon - Liverworts is the mismatched pair.

Why other options are wrong:
- Option A: Phaneros - Visible: This is a correct match.
- Option B: Kryptos - Concealed: This is a correct match.
- Option C: Gymno - Naked: This is a correct match.
- Option D: Bryon - Liverworts: This is incorrect because Bryon refers to mosses, not liverworts.

Key Concepts:
- Plant classification
- Botanical terminology
- Bryophytes

Memory Aids:
- Remember that Bryon refers to mosses.

Quick Tips:
- Review botanical terms and their meanings.

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[A]: Chromosome number and chromosome morphology are helpful in the elucidation of certain phylgenetic problems.

[R]: The external characters of seeds are of great value in Separating closely related genera and species.

View answer and explanation

Correct option: B

Both A and R are true and R is not the correct explanation of A

Option B (Both A and R are true and R is not the correct explanation of A) is correct because both the assertion and reason are true statements, but the reason does not explain the assertion.

Solution approach

Correct Answer + Core Reason: Both A and R are true and R is not the correct explanation of A. Both statements are correct, but unrelated.

Step-by-Step Solution:

Step 1: Analyze Assertion (A): Chromosome number and chromosome morphology are helpful in the elucidation of certain phylogenetic problems. This is true because chromosome characteristics can provide valuable insights into evolutionary relationships.

Step 2: Analyze Reason (R): The external characters of seeds are of great value in separating closely related genera and species. This is also true. Seed characteristics are often used in taxonomy.

Step 3: Determine if R explains A: The reason (R) does not explain the assertion (A). Seed characteristics and chromosome characteristics are independent lines of evidence used in classification.

Why other options are wrong:
- Option A: R does not explain A.
- Option C: Both A and R are true.
- Option D: Both A and R are true.

Key Concepts:
- Phylogeny
- Chromosome morphology
- Seed characteristics
- Plant taxonomy

Memory Aids:
- Chromosomes and seeds are independent sources of taxonomic information.

Quick Tips:
- Consider whether the reason directly explains the assertion.

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[A]: In ferns, prothallus is club shaped.

[R]: Prothallus is derived from club shaped zoosporangia.

View answer and explanation

Correct option: D

Both A and R are false

Option D (Both A and R are false) is correct because the prothallus in ferns is heart-shaped, not club-shaped, and it does not arise from club-shaped zoosporangia.

Solution approach

Correct Answer + Core Reason: Both A and R are false because the prothallus is heart-shaped and not derived from zoosporangia.

Step-by-Step Solution:

Step 1: Evaluate the assertion: In ferns, prothallus is club shaped. This is incorrect; the prothallus is heart-shaped.

Step 2: Evaluate the reason: Prothallus is derived from club shaped zoosporangia. This is also incorrect; prothallus develops from spores.

Step 3: Determine the correct option based on the evaluation of the assertion and reason.

Why other options are wrong:
- Option A: Both assertion and reason are not true.
- Option B: Both assertion and reason are not true.
- Option C: The assertion is not true.

Key Concepts:
- Fern Life Cycle
- Prothallus
- Spores

Memory Aids:
- Prothallus is heart-shaped (easy to visualize).

Quick Tips:
- Know the shape and origin of the prothallus in ferns.

39 Hard

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An edible rhodophyte is?

View answer and explanation

Correct option: C

Porphyra

Option C (Porphyra) is correct because Porphyra is a red alga that is widely cultivated and consumed as a food source, particularly in East Asia (e.g., nori in sushi).

Solution approach

Correct Answer + Core Reason: Porphyra. Porphyra is an edible red alga.

Step-by-Step Solution:

Step 1: Consider the different types of red algae.

Step 2: Porphyra is a red alga that is commonly used as food, particularly in Japanese cuisine (nori).

Why other options are wrong:
- Option A: Polysiphonia: Polysiphonia is a red alga, but it is not commonly consumed as food.
- Option B: Batrachospermum: Batrachospermum is a freshwater red alga and is not commonly consumed as food.
- Option D: Corallina: Corallina is a calcareous red alga and is not commonly consumed as food.

Key Concepts:
- Edible algae
- Types of red algae

Memory Aids:
- Porphyra = Nori (sushi)

Quick Tips:
- Remember that Porphyra is a common edible red alga.

40 Hard

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Select the odd one w.r.t. prothallus.

View answer and explanation

Correct option: A

Unicellular

Option A (Unicellular) is correct because prothallus is multicellular, photosynthetic, thalloid gametophyte and free living.

Solution approach

Correct Answer + Core Reason: Unicellular. Prothallus is multicellular.

Step-by-Step Solution:

Step 1: Define prothallus: the gametophyte of a fern or other pteridophyte.

Step 2: Recall the characteristics of the prothallus: it is a small, heart-shaped, photosynthetic, thalloid gametophyte that is free-living.

Step 3: Recognize that the prothallus is multicellular, not unicellular.

Step 4: Conclude that unicellular is the odd one out.

Why other options are wrong:
- Option B: The prothallus is photosynthetic.
- Option C: The prothallus is a thalloid gametophyte.
- Option D: The prothallus is free-living.

Key Concepts:
- Prothallus
- Gametophyte
- Pteridophytes

Memory Aids:
- Remember that the prothallus is a small, heart-shaped, multicellular structure.

Quick Tips:
- Understand the characteristics of the prothallus.

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Male and female gametophytes are independent and free-living in

View answer and explanation

Correct option: D

Sphagnum

Option D (Sphagnum) is correct because Sphagnum (a moss) has independent and free-living male and female gametophytes.

Solution approach

Correct Answer + Core Reason: Sphagnum. Male and female gametophytes are independent and free-living in Sphagnum.

Step-by-Step Solution:

Step 1: Recall the life cycles of the plants listed in the options.

Step 2: Remember that in bryophytes like Sphagnum, the gametophyte is the dominant phase and can be independent and free-living.

Step 3: Recognize that Sphagnum has independent male and female gametophytes.

Step 4: Conclude that Sphagnum is the correct answer.

Why other options are wrong:
- Option A: Mustard (a flowering plant) has a reduced gametophyte that is dependent on the sporophyte.
- Option B: Castor (a flowering plant) has a reduced gametophyte that is dependent on the sporophyte.
- Option C: Pinus (a gymnosperm) has a reduced gametophyte that is dependent on the sporophyte.

Key Concepts:
- Gametophyte
- Sporophyte
- Bryophytes
- Gymnosperms
- Angiosperms

Memory Aids:
- Remember that bryophytes (like Sphagnum) have a dominant gametophyte phase.

Quick Tips:
- Understand the life cycles of different plant groups.

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Nostoc fixes dinitrogen in symbiotic association with the following
I. Alnus II. Gunnera
III. Anthoceros IV. Casuarina

View answer and explanation

Correct option: B

II and III

Option B (II and III) is correct because Nostoc forms symbiotic associations with Gunnera and Anthoceros.

Solution approach

Correct Answer + Core Reason: II and III. Nostoc fixes dinitrogen in symbiotic association with Gunnera and Anthoceros.

Step-by-Step Solution:

Step 1: Recall the symbiotic relationships of Nostoc.\nNostoc is a cyanobacterium known for its nitrogen-fixing abilities. It forms symbiotic associations with various plants.

Step 2: Identify the correct associations.\nNostoc is known to associate with:
- Gunnera (a flowering plant)
- Anthoceros (a bryophyte)
\nNostoc does not typically form symbiotic associations with Alnus or Casuarina (both of which are associated with Frankia for nitrogen fixation).

Step 3: Conclusion.\nTherefore, the correct answer is II and III.

Why other options are wrong:
- Option A: I and II is incorrect because Nostoc does not typically associate with Alnus.
- Option C: I and III is incorrect because Nostoc does not typically associate with Alnus.
- Option D: I and IV is incorrect because Nostoc does not typically associate with Alnus or Casuarina.

Key Concepts:
- Symbiotic relationships
- Nitrogen fixation
- Nostoc
- Gunnera
- Anthoceros

Memory Aids:
- Remember that Nostoc is a cyanobacterium that can form symbiotic relationships with plants like Gunnera and Anthoceros for nitrogen fixation.

Quick Tips:
- Know common nitrogen-fixing bacteria and their plant associations (e.g., Rhizobium with legumes, Frankia with Alnus/Casuarina, Nostoc with Gunnera/Anthoceros).

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Dominant stage in bryophytes is

View answer and explanation

Correct option: B

Independent gametophyte

Option B (Independent gametophyte) is correct because the gametophyte is the dominant and independent phase in bryophytes.

Solution approach

Correct Answer + Core Reason: Independent gametophyte. The gametophyte is the dominant, photosynthetic, and independent phase in bryophytes.

Step-by-Step Solution:

Step 1: Identify the life cycle of bryophytes.

Step 2: Recall that bryophytes have a dominant gametophyte stage.

Step 3: Understand that the gametophyte is independent and photosynthetic.

Step 4: The sporophyte is dependent on the gametophyte for nutrition.

Why other options are wrong:
- Option A: The sporophyte is dependent on the gametophyte in bryophytes, not independent.
- Option C: This option combines both independent sporophyte and gametophyte, but only the gametophyte is independent.
- Option D: The gametophyte is independent, not dependent.

Key Concepts:
- Bryophyte life cycle
- Gametophyte and sporophyte phases
- Dominant phase in bryophytes

Memory Aids:
- Remember that "G"ametophyte is "G"reat in bryophytes (dominant).

Quick Tips:
- Focus on the life cycle and the roles of gametophyte and sporophyte.

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Largest gametophyte is found in

View answer and explanation

Correct option: B

Polytrichum

Option B (Polytrichum) is correct because Polytrichum, a moss, has a relatively large and well-developed gametophyte compared to other plants listed.

Solution approach

Correct Answer + Core Reason: Polytrichum. Polytrichum has a relatively large gametophyte.

Step-by-Step Solution:

Step 1: Recall the characteristics of the gametophytes in different plant groups.

Step 2: Understand that Polytrichum is a moss with a well-developed gametophyte.

Step 3: Compare the gametophyte size in the given options.

Why other options are wrong:
- Option A: Angiosperms have a reduced gametophyte that is dependent on the sporophyte.
- Option C: Nephrolepis is a fern, and while ferns have a free-living gametophyte (prothallus), it is not as large as the Polytrichum gametophyte.
- Option D: Cycas is a gymnosperm with a reduced gametophyte that is dependent on the sporophyte.

Key Concepts:
- Gametophyte
- Polytrichum
- Plant Life Cycles

Memory Aids:
- Remember that Polytrichum is a moss with a relatively large gametophyte.

Quick Tips:
- Focus on the fact that Polytrichum is a moss with a prominent gametophyte.

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Select the odd one w.r.t gymnosperms.

View answer and explanation

Correct option: C

Embryo sac has 3 celled egg apparatus

Option C (Embryo sac has 3 celled egg apparatus) is correct. Gymnosperms have a female gametophyte (embryo sac) with an archegonium, which contains the egg. The egg apparatus is not 3-celled in gymnosperms.

Solution approach

Correct Answer + Core Reason: Embryo sac has 3 celled egg apparatus. The embryo sac in gymnosperms does not have a 3-celled egg apparatus like angiosperms. It contains an archegonium with an egg cell.

Step-by-Step Solution:

Step 1: Recall the characteristics of gymnosperms.

Step 2: Consider the structure of the ovule in gymnosperms.

Step 3: Remember that gymnosperms have an archegonium containing the egg cell.

Step 4: Understand that the 3-celled egg apparatus (egg cell and two synergids) is a feature of angiosperms, not gymnosperms.

Why other options are wrong:
- Option A: Ovules are indeed not enclosed by an ovary wall in gymnosperms.
- Option B: Gymnosperms generally have tap roots.
- Option D: Mycorrhizal associations are common in gymnosperm roots.

Key Concepts:
- Gymnosperm ovule
- Archegonium
- Egg apparatus
- Mycorrhiza

Memory Aids:
- Gymnosperms: Archegonium, No 3-celled egg apparatus

Quick Tips:
- Remember the differences between gymnosperm and angiosperm ovules.

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Which of the following plant materials, is an efficient water imbibant?

View answer and explanation

Correct option: C

Agar

Option C (Agar) is correct because agar has a high water-holding capacity and is thus an efficient water imbibant.

Solution approach

Correct Answer + Core Reason: Agar. Agar is a polysaccharide derived from red algae and has a high water-holding capacity, making it an efficient water imbibant.

Step-by-Step Solution:

Step 1: Identify the key term: Water imbibant.

Step 2: Recall the properties of the given plant materials: Lignin, Pectin, Agar, and Cellulose.

Step 3: Consider the water-holding capacity of each material.

Step 4: Determine which material has the highest water-holding capacity. Agar has a high water-holding capacity and is used in various applications for this reason.

Step 5: Conclude that agar is the correct answer.

Why other options are wrong:
- Option A: Lignin is a complex polymer that provides rigidity to plant cell walls but is not a significant water imbibant.
- Option B: Pectin is a structural polysaccharide found in plant cell walls and has some water-holding capacity, but not as high as agar.
- Option D: Cellulose is a structural polysaccharide found in plant cell walls and has some water-holding capacity, but not as high as agar.

Key Concepts:
- Plant materials
- Water imbibition
- Agar

Memory Aids:
- Remember that agar is used in laboratories to solidify media because of its water-holding capacity.

Quick Tips:
- Associate agar with its ability to absorb and hold water.

47 Hard

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Which of the following statements are correct for Cycas
I. The stem is unbranched
II. The pinnately compound leaves persist for few years
III. Having symbiotic association with

{N_2}

fixing cynobacteria.
IV. Cycas plants are monoceious with mycorrhizal association.

View answer and explanation

Correct option: D

I, II & III

Option D (I, II & III) is correct. Cycas has an unbranched stem, pinnately compound leaves that persist for a few years, and a symbiotic association with nitrogen-fixing cyanobacteria.

Solution approach

Correct Answer + Core Reason: I, II & III. Cycas has an unbranched stem, pinnately compound leaves that persist for a few years, and a symbiotic association with nitrogen-fixing cyanobacteria. Cycas is dioecious, not monoecious.

Step-by-Step Solution:

Step 1: Evaluate statement I: The stem is unbranched - Correct.

Step 2: Evaluate statement II: The pinnately compound leaves persist for few years - Correct.

Step 3: Evaluate statement III: Having symbiotic association with ${N_2}$ fixing cynobacteria - Correct.

Step 4: Evaluate statement IV: Cycas plants are monoceious with mycorrhizal association - Incorrect. Cycas is dioecious.

Step 5: Choose the option with correct statements: I, II & III.

Why other options are wrong:
- Option A: Statement IV is incorrect.
- Option B: Statement IV is incorrect.
- Option C: Statement IV is incorrect.

Key Concepts:
- Cycas characteristics
- Stem structure
- Leaf type
- Symbiotic associations
- Monoecious vs. Dioecious

Memory Aids:
- Cycas: Unbranched, Pinnate, Cyanobacteria

Quick Tips:
- Remember the key features of Cycas.

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Given below are two statements : One labelled as Assertion A and the other labelled as Reason R :

Assertion A : In gymnosperms the pollen grains are released from the microsporangium and carried by air
currents.

Reason R : Air currents carry the pollen grains to the mouth of the archegonia where the male gametes are
discharged and pollen tube is not formed.

In the light of the above statements, choose the correct answer from the options given below :

View answer and explanation

Correct option: A

A is true but R is false

Option A (A is true but R is false) is correct. Assertion A is true; gymnosperms release pollen grains carried by air. Reason R is false; gymnosperms do form pollen tubes.

Solution approach

Correct Answer + Core Reason: A is true but R is false. Gymnosperms release pollen grains that are carried by air currents, but they do form pollen tubes to deliver the male gametes to the archegonia.

Step-by-Step Solution:

Step 1: Evaluate Assertion A: In gymnosperms the pollen grains are released from the microsporangium and carried by air currents - True.

Step 2: Evaluate Reason R: Air currents carry the pollen grains to the mouth of the archegonia where the male gametes are discharged and pollen tube is not formed - False. Pollen tube is formed in gymnosperms.

Step 3: Choose the option that matches the evaluation: A is true but R is false.

Why other options are wrong:
- Option B: Assertion A is true.
- Option C: Reason R is false.
- Option D: Reason R is false.

Key Concepts:
- Gymnosperm reproduction
- Pollen dispersal
- Pollen tube formation

Memory Aids:
- Gymnosperms: Air dispersal, Pollen tube

Quick Tips:
- Remember that gymnosperms form pollen tubes.

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[A]: Either megasporophylls or microsporophylls are found in Gymnosperms.

[R]: Both mega and microsporophylls are common in Gymnosperms. Megasporophylls are smaller than microsporophylls.

View answer and explanation

Correct option: D

Both A and R are false

Option D (Both A and R are false) is correct because gymnosperms have both megasporophylls and microsporophylls, and megasporophylls are generally larger than microsporophylls.

Solution approach

Correct Answer + Core Reason: Both A and R are false. Gymnosperms have both megasporophylls and microsporophylls, and megasporophylls are generally larger.

Step-by-Step Solution:

Step 1: Analyze Assertion [A]: Either megasporophylls or microsporophylls are found in Gymnosperms.

Step 2: Recall that Gymnosperms have both megasporophylls (female) and microsporophylls (male).

Step 3: Therefore, Assertion [A] is false.

Step 4: Analyze Reason [R]: Both mega and microsporophylls are common in Gymnosperms. Megasporophylls are smaller than microsporophylls.

Step 5: Recall that megasporophylls are generally larger than microsporophylls in gymnosperms.

Step 6: Therefore, Reason [R] is false.

Why other options are wrong:
- Option A: Both A and R are true and R is the correct explanation of A - Incorrect because both A and R are false.
- Option B: Both A and R are true and R is not the correct explanation of A - Incorrect because both A and R are false.
- Option C: A is true but R is false - Incorrect because A is also false.
- Option D: Both A and R are false - Correct because both A and R are false.

Key Concepts:
- Gymnosperms
- Megasporophylls
- Microsporophylls
- Plant reproduction

Memory Aids:
- Remember that Gymnosperms have both male and female reproductive structures.

Quick Tips:
- Carefully analyze each statement before determining the correct answer.

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In Pinus, the development of endosperm is

View answer and explanation

Correct option: A

A pre-fertilization event

Option A (A pre-fertilization event) is correct because in Pinus, the endosperm develops before fertilization, making it a pre-fertilization event.

Solution approach

Correct Answer + Core Reason: A pre-fertilization event. In Pinus, the endosperm is formed before fertilization.

Step-by-Step Solution:

Step 1: Recall endosperm development in gymnosperms.\nIn gymnosperms like Pinus, the endosperm is formed before fertilization. It is a haploid tissue derived from the female gametophyte.

Step 2: Contrast with angiosperms.\nIn angiosperms, the endosperm is formed after fertilization and is triploid (3n) due to the fusion of a sperm nucleus with the polar nuclei.

Step 3: Conclusion.\nTherefore, the correct answer is A pre-fertilization event.

Why other options are wrong:
- Option B: A post-fertilization event is incorrect because endosperm development in Pinus occurs before fertilization.
- Option C: Absent is incorrect because endosperm is present in Pinus.
- Option D: Parthenogenetic is incorrect because parthenogenesis refers to development without fertilization, which is not the case for endosperm development in Pinus.

Key Concepts:
- Endosperm development in gymnosperms and angiosperms
- Pre-fertilization vs. post-fertilization events
- Pinus

Memory Aids:
- Gymnosperms have a pre-fertilization endosperm, while angiosperms have a post-fertilization endosperm.

Quick Tips:
- Remember the difference in endosperm development between gymnosperms and angiosperms.

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Classification done on the basis of cytological information, chromosome structure and their behavior, is known as

View answer and explanation

Correct option: B

Cytotaxonomy

Option B (Cytotaxonomy) is correct because it specifically refers to classification based on cytological information, chromosome structure, and behavior.

Solution approach

Correct Answer + Core Reason: Cytotaxonomy. Classification based on cytological information, chromosome structure and behavior is known as cytotaxonomy.

Step-by-Step Solution:

Step 1: Define the terms.\nCytotaxonomy: Classification based on cytological information (cell structure, function), chromosome structure, and behavior.\nMolecular classification: Classification based on molecular data like DNA and protein sequences.\nChemotaxonomy: Classification based on chemical constituents of the plant.\nKaryotaxonomy: Classification based on karyotype (number, size, and shape of chromosomes).

Step 2: Identify the correct definition.\nThe question specifically mentions cytological information, chromosome structure, and behavior. This directly corresponds to the definition of cytotaxonomy.

Step 3: Conclusion.\nTherefore, the correct answer is Cytotaxonomy.

Why other options are wrong:
- Option A: Molecular classification is based on molecular data, not cytological information.
- Option C: Chemotaxonomy is based on chemical constituents, not cytological information.
- Option D: Karyotaxonomy is specifically about the karyotype, while the question includes broader cytological information.

Key Concepts:
- Cytotaxonomy
- Molecular classification
- Chemotaxonomy
- Karyotaxonomy

Memory Aids:
- Cyto- refers to cell, so Cytotaxonomy is related to cell-based classification.

Quick Tips:
- Understand the prefixes: Cyto- (cell), Chemo- (chemical), Karyo- (nucleus/chromosomes).

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The cones bearing megasporophyll with ovules are called

View answer and explanation

Correct option: B

Female strobili

Option B (Female strobili) is correct because megasporophylls with ovules are found in female cones, also known as female strobili.

Solution approach

Correct Answer + Core Reason: Female strobili. Cones bearing megasporophyll with ovules are called female strobili.

Step-by-Step Solution:

Step 1: Recall the structure of cones in gymnosperms.

Step 2: Consider the function of megasporophylls and ovules. Megasporophylls bear ovules, which develop into seeds. These are found in female cones (female strobili).

Step 3: Conclusion: The cones bearing megasporophyll with ovules are called female strobili.

Why other options are wrong:
- Option A: Male strobili bear microsporophylls, which produce pollen.
- Option C: Megasporangia are structures within the ovules where megaspores develop.
- Option D: Microsporangia are structures where microspores (pollen) develop.

Key Concepts:
- Gymnosperm cones
- Megasporophylls and microsporophylls

Memory Aids:
- Remember that mega- refers to female structures.

Quick Tips:
- Differentiate between male and female cones in gymnosperms.

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Which of the following can be regarded as seedless vascular plants?

View answer and explanation

Correct option: D

Pteridophytes

Option D (Pteridophytes) is correct because pteridophytes are vascular plants that reproduce via spores, not seeds.

Solution approach

Correct Answer + Core Reason: Pteridophytes. Pteridophytes are vascular plants that do not produce seeds.

Step-by-Step Solution:

Step 1: Recall the characteristics of angiosperms, gymnosperms, bryophytes, and pteridophytes.

Step 2: Consider the presence or absence of seeds and vascular tissue. Angiosperms and gymnosperms are seed-bearing vascular plants. Bryophytes are non-vascular plants. Pteridophytes are vascular plants that reproduce via spores, not seeds.

Step 3: Conclusion: Pteridophytes can be regarded as seedless vascular plants.

Why other options are wrong:
- Option A: Angiosperms are seed-bearing vascular plants.
- Option B: Gymnosperms are seed-bearing vascular plants.
- Option C: Bryophytes are non-vascular plants.

Key Concepts:
- Vascular plants vs. non-vascular plants
- Seed-bearing vs. seedless plants

Memory Aids:
- Remember that pteridophytes are seedless vascular plants.

Quick Tips:
- Differentiate between vascular and non-vascular plants, and seed-bearing and seedless plants.

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Meiosis in Dryopteris takes place during

View answer and explanation

Correct option: D

Spore formation

Option D (Spore formation) is correct because meiosis in pteridophytes like Dryopteris occurs during spore formation within sporangia.

Solution approach

Correct Answer + Core Reason: Spore formation. Meiosis produces haploid spores in pteridophytes.

Step-by-Step Solution:

Step 1: Recall the life cycle of pteridophytes (ferns).

Step 2: Understand that pteridophytes have a dominant sporophyte (2n) and a less conspicuous gametophyte (n).

Step 3: Recognize that meiosis occurs in sporangia on the sporophyte to produce haploid spores (n).

Step 4: The spores then germinate to form the gametophyte.

Why other options are wrong:
- Option A: Gamete formation: Gametes are formed by mitosis in the gametophyte.
- Option B: Spore germination: Spore germination is a mitotic process.
- Option C: Zygote formation: Zygote formation is the fusion of gametes (fertilization), not meiosis.

Key Concepts:
- Pteridophyte life cycle
- Alternation of generations
- Meiosis and spore formation
- Gamete formation

Memory Aids:
- Remember that meiosis always results in the formation of haploid spores.

Quick Tips:
- Know the difference between meiosis (reduction division) and mitosis (equational division) in plant life cycles.

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Spores with chloroplast is present in

View answer and explanation

Correct option: B

Equisetum

Option B (Equisetum) is correct because Equisetum spores contain chloroplasts, allowing them to photosynthesize for a short period after dispersal.

Solution approach

Correct Answer + Core Reason: Equisetum. Equisetum spores contain chloroplasts.

Step-by-Step Solution:

Step 1: Recall the characteristics of spores in different plant groups.

Step 2: Identify which plant group has spores with chloroplasts.

Step 3: Equisetum spores contain chloroplasts.

Why other options are wrong:
- Option A: Selaginella spores do not typically contain chloroplasts.
- Option C: Puccinia is a fungus, not a plant, and its spores do not contain chloroplasts.
- Option D: Rhizopus is a fungus, not a plant, and its spores do not contain chloroplasts.

Key Concepts:
- Spores: Reproductive cells in plants and fungi.
- Chloroplasts: Organelles responsible for photosynthesis.

Memory Aids:
- Associate Equisetum with its unique spores containing chloroplasts.

Quick Tips:
- Remember that Equisetum is a unique pteridophyte with photosynthetic spores.

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Assertion: Each cell of the embryo sac is haploid in angiosperms.
Reason: In angiosperms, meiosis preceeds embryo sac formation.

View answer and explanation

Correct option: A

If both assertion and reason are correct and the reason is a correct explanation of the assertion.

Option A is correct because both the assertion and the reason are correct, and the reason correctly explains the assertion. Meiosis precedes embryo sac formation, resulting in haploid cells.

Solution approach

Correct Answer + Core Reason: If both assertion and reason are correct and the reason is a correct explanation of the assertion. The cells of the embryo sac are haploid because they are formed after meiosis.

Step-by-Step Solution:

Step 1: Analyze the assertion: Each cell of the embryo sac is haploid.

Step 2: Analyze the reason: Meiosis precedes embryo sac formation, reducing the chromosome number to haploid.

Step 3: Connect the reason to the assertion: Meiosis results in haploid cells, which then form the embryo sac.

Step 4: Conclusion: Both assertion and reason are correct, and the reason explains the assertion.

Why other options are wrong:
- Option A: Correct because both assertion and reason are correct and the reason is a correct explanation of the assertion.
- Option B: Incorrect because the reason is a correct explanation of the assertion.
- Option C: Incorrect because the assertion is correct.
- Option D: Incorrect because both the assertion and reason are correct.

Key Concepts:
- Meiosis and its role in reducing chromosome number
- Embryo sac formation in angiosperms
- Haploid and diploid cells

Memory Aids:
- Meiosis = "Halving" the chromosome number.

Quick Tips:
- Remember that meiosis always results in haploid cells.

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Selaginella has a tendency to form seed, called seed habit because it follows

View answer and explanation

Correct option: C

Both (1) and (2)

Option C (Both (1) and (2)) is correct because Selaginella exhibits both retention of the megaspore and heterospory, which are key characteristics associated with the evolution of the seed habit.

Solution approach

Correct Answer + Core Reason: Both (1) and (2). Selaginella exhibits both retention of the megaspore and heterospory, key characteristics of seed habit.

Step-by-Step Solution:

Step 1: Define seed habit.

Step 2: Identify the characteristics associated with seed habit.

Step 3: Heterospory (production of microspores and megaspores) is important.

Step 4: Retention of the megaspore within the megasporangium is also important.

Step 5: Selaginella exhibits both of these characteristics.

Why other options are wrong:
- Option A: Retention of megaspore alone is not sufficient.
- Option B: Heterospory alone is not sufficient.
- Option D: Both factors are involved.

Key Concepts:
- Seed habit
- Heterospory
- Megaspore retention

Memory Aids:
- Remember that both heterospory and megaspore retention are needed for seed habit.

Quick Tips:
- Understand the evolutionary steps towards seed formation.

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In the alternation of generations the sporophytic generations is …A… and the gametophytic generation is …B… . Here A and B refer to

View answer and explanation

Correct option: A

A-2n; B-n

Option A (A-2n; B-n) is correct because the sporophytic generation is diploid (2n) and the gametophytic generation is haploid (n).

Solution approach

Correct Answer + Core Reason: A-2n; B-n. The sporophytic generation is diploid (2n), and the gametophytic generation is haploid (n).

Step-by-Step Solution:

Step 1: Define sporophyte and gametophyte:
- Sporophyte: Diploid (2n) generation that produces spores.
- Gametophyte: Haploid (n) generation that produces gametes.

Step 2: Conclude: A (sporophyte) is 2n, and B (gametophyte) is n.

Why other options are wrong:
- Option B (A-n; B-2n): This is incorrect because the sporophyte is diploid (2n), not haploid (n).
- Option C (A-n; B-n): This is incorrect because the sporophyte is diploid (2n), not haploid (n).
- Option D (A-2n; B-2n): This is incorrect because the gametophyte is haploid (n), not diploid (2n).

Key Concepts:
- Sporophyte and gametophyte ploidy
- Alternation of generations

Memory Aids:
- Sporophyte = 2n, Gametophyte = n

Quick Tips:
- Remember the ploidy level of sporophyte and gametophyte.

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While entering in the neck of a fern archegonium, sperms shows

View answer and explanation

Correct option: B

Chemotaxy

Option B (Chemotaxy) is correct because sperm movement towards the archegonium in ferns is guided by chemical signals.

Solution approach

Correct Answer + Core Reason: Chemotaxy. Sperm movement is directed by chemical attractants.

Step-by-Step Solution:

Step 1: Understand the process of fertilization in ferns.

Step 2: Fern sperm needs to swim to the archegonium for fertilization.

Step 3: The archegonium releases chemical substances that attract the sperm.

Step 4: This movement of sperm towards the chemical stimulus is called chemotaxy.

Why other options are wrong:
- Option A: Phototaxy is movement in response to light, which is not the primary mechanism for sperm guidance in ferns.
- Option C: Thermotaxy is movement in response to temperature gradients, not relevant in this context.
- Option D: Cyclosis is the movement of cytoplasm within a cell and is not related to sperm movement towards the archegonium.

Key Concepts:
- Fertilization in ferns
- Chemotaxy
- Archegonium
- Sperm movement

Memory Aids:
- "Chemo" refers to chemicals, so chemotaxy is movement in response to chemicals.

Quick Tips:
- Remember that chemotaxis is a common mechanism for guiding cells towards specific locations.

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Assertion: Liverworts fail to spread to a new locality through fragmentation.
Reason: Gemmae are helpful in propagating liverworts in different locality.

View answer and explanation

Correct option: B

If both assertion and reason are correct but reason is not a correct explanation of the assertion.

Option B (If both assertion and reason are correct but reason is not a correct explanation of the assertion) is correct because both the assertion and reason are true, but the reason doesn't explain why liverworts fail to spread through fragmentation.

Solution approach

Correct Answer + Core Reason: If both assertion and reason are correct but reason is not a correct explanation of the assertion. Both statements are true, but the reason doesn't explain the assertion.

Step-by-Step Solution:

Step 1: Evaluate the assertion: Liverworts fail to spread to a new locality through fragmentation. This is generally true, as fragmentation is not their primary mode of dispersal.

Step 2: Evaluate the reason: Gemmae are helpful in propagating liverworts in different locality. This is also true, as gemmae are specialized structures for asexual reproduction and dispersal.

Step 3: Determine if the reason explains the assertion: The reason does not explain why liverworts fail to spread through fragmentation. Gemmae are a *different* method of propagation, not a reason why fragmentation fails.

Step 4: Conclude that both the assertion and reason are correct, but the reason is not a correct explanation of the assertion.

Why other options are wrong:
- Option A: The reason does not explain the assertion.
- Option C: The assertion is correct.
- Option D: Both the assertion and reason are correct.

Key Concepts:
- Fragmentation
- Gemmae
- Asexual reproduction
- Liverworts

Memory Aids:
- Remember that gemmae are specialized structures for asexual reproduction in liverworts.

Quick Tips:
- Carefully analyze the relationship between the assertion and the reason.

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