Q1. Features of angiosperms – which are correct? (i) Range from Wolffia to Eucalyptus in size. (ii) Provide food, fodder, fuel and medicines. (iii) Possess naked seeds not enclosed in fruits.
Correct Answer: (a)
Angiosperms vary from tiny Wolffia to huge Eucalyptus (i) and are economically important (ii). However, their seeds are enclosed within fruits, not naked—that is a gymnosperm feature (iii false). Hence, (i) and (ii) are correct.
Q2. Match the plant groups with the specific examples from the chapter:
Column-I (Group)
Column-II (Example)
A. Liverwort
1. Marchantia
B. Moss
2. Funaria
C. Pteridophyte
3. Salvinia
D. Gymnosperm
4. Cycas
Correct Answer: (a)
Marchantia is a liverwort (1). Funaria is a moss (2). Salvinia is a pteridophyte (3). Cycas is a gymnosperm (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q3. Algin is commercially obtained from:
Correct Answer: (b)
Algin (or alginic acid) is a gelatinous polysaccharide extracted from the cell walls of brown algae, particularly species like Laminaria, Macrocystis, and Sargassum. It is used as a thickening, stabilising, and emulsifying agent in food, pharmaceutical, and cosmetic industries. Brown algae produce algin as a structural component that helps them withstand wave action in marine environments. Green and red algae do not produce algin; they have other cell wall polymers like cellulose, pectin, or carrageenan. Thus, algin is a characteristic product of the Phaeophyceae.
Q4. Needle-like leaves, thick cuticle and sunken stomata are typical of:
Correct Answer: (b)
Conifers (e.g., Pinus, Cedrus) are gymnosperms adapted to dry and cold conditions. Their needle‑like leaves reduce surface area, thereby minimising water loss. A thick cuticle further reduces transpiration, and sunken stomata (located in pits) create a humid microclimate that lowers evaporation rates. These xeromorphic features help conifers survive in environments where water is limited. Liverworts, ferns, and mosses lack such adaptations and generally require moist habitats.
Q5. Match the life cycle dominance with the representative plant:
Column-I
Column-II
A. Dominant gametophyte, dependent sporophyte
1. Moss
B. Dominant sporophyte, independent gametophyte
2. Fern
C. Dominant sporophyte, reduced gametophyte retained
3. Pinus
D. Predominantly thalloid haploid stage only
4. Ulothrix
Correct Answer: (a)
Moss (bryophyte) has dominant gametophyte and dependent sporophyte (1). Fern (pteridophyte) has dominant sporophyte and an independent gametophyte (2). Pinus (gymnosperm) has dominant sporophyte with a highly reduced gametophyte retained (3). Ulothrix (alga) is predominantly haploid thalloid (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q6. Fucoxanthin is the characteristic pigment of:
Correct Answer: (b)
Fucoxanthin is a xanthophyll pigment that imparts the brown or olive‑green colour to brown algae (Phaeophyceae). It masks the green chlorophylls and allows these algae to absorb light in the blue‑green region, which penetrates deeper into water. This pigment is not found in green algae (Chlorophyceae), red algae (Rhodophyceae), or bryophytes. Fucoxanthin also has antioxidant properties and is being studied for health benefits. Its presence is a defining characteristic of the Phaeophyceae.
Q7. In gymnosperms, which reproduction statements are correct? (i) Microsporangiate cones bear microsporophylls and microsporangia. (ii) Megasporophylls with ovules form female cones. (iii) Pollen tube carries male gametes to archegonia.
Correct Answer: (d)
All three statements are true for gymnosperms. Male cones contain microsporophylls and microsporangia (i). Female cones consist of megasporophylls bearing ovules (ii). The pollen tube carries male gametes to the archegonia (iii). These features are fundamental to gymnosperm reproduction.
Q8. Match the pteridophyte classes with their examples:
Column-I (Class)
Column-II (Example)
A. Psilopsida
1. Psilotum
B. Lycopsida
2. Selaginella, Lycopodium
C. Sphenopsida
3. Equisetum
D. Pteropsida
4. Dryopteris, Pteris, Adiantum
Correct Answer: (a)
Psilopsida includes Psilotum (whisk ferns) (1). Lycopsida includes Selaginella and Lycopodium (club mosses) (2). Sphenopsida includes Equisetum (horsetails) (3). Pteropsida includes ferns like Dryopteris, Pteris, and Adiantum (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q9. Match the algal classes with their respective pigments:
Column-I (Class)
Column-II (Pigments)
A. Chlorophyceae
1. Chlorophyll a, c, fucoxanthin
B. Phaeophyceae
2. Chlorophyll a, b
C. Rhodophyceae
3. Chlorophyll a, d, phycoerythrin
Correct Answer: (a)
Chlorophyceae (green algae) contain chlorophyll a and b, similar to higher plants. Phaeophyceae (brown algae) possess chlorophyll a, c, and the xanthophyll fucoxanthin. Rhodophyceae (red algae) have chlorophyll a, d, and the phycobilin pigment phycoerythrin. These pigment compositions are characteristic of each class and influence their colour and depth distribution. Thus, the correct matching is A‑2, B‑1, C‑3.
Q10. Assertion: Kelp are examples of large marine plant bodies.
Reason: Kelp belong to Chlorophyceae that bear fucoxanthin pigment.
Correct Answer: (c)
The assertion is true: kelps are large, multicellular brown algae that form underwater forests in cold, nutrient‑rich waters. However, the reason is false because kelps belong to the Phaeophyceae (brown algae), not Chlorophyceae (green algae). Brown algae contain the pigment fucoxanthin, which gives them their characteristic colour. Since the reason incorrectly assigns kelp to the wrong algal class, it cannot explain the assertion. Thus, assertion true, reason false.
Q11. Match the groups with typical reserves or features:
Column-I
Column-II
A. Chlorophyceae
1. Pyrenoids
B. Phaeophyceae
2. Laminarin and mannitol
C. Rhodophyceae
3. Floridean starch
D. Gymnosperms
4. Naked ovules and seeds
Correct Answer: (a)
Chlorophyceae have pyrenoids in chloroplasts (1). Phaeophyceae store laminarin and mannitol (2). Rhodophyceae store floridean starch (3). Gymnosperms have naked ovules and seeds (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q12. Gymnosperms – which statements are correct? (i) Have ovules not enclosed by ovary wall. (ii) Produce naked seeds after fertilisation. (iii) Always have male and female cones on different trees.
Correct Answer: (a)
Gymnosperms have ovules not enclosed by an ovary (i) and produce naked seeds (ii). However, not all are dioecious; many (e.g., Pinus) are monoecious, so (iii) is false. Thus, only (i) and (ii) are correct.
Q13. In moss life cycle, which statements are correct? (i) Protonema arises from spore. (ii) Leafy stage arises from protonema as lateral bud. (iii) Rhizoids are unicellular.
Correct Answer: (a)
Moss spores germinate to form a protonema (i), from which buds arise to form the leafy stage (ii). Moss rhizoids are multicellular and branched, not unicellular (iii false). Therefore, (i) and (ii) are correct.
Q14. Gemmae in Marchantia are:
Correct Answer: (c)
Gemmae are small, multicellular, green asexual buds produced in specialised cup‑like structures called gemma cups on the thallus of Marchantia (a liverwort). When detached by rain or other means, they germinate to form new gametophytic plants. Gemmae are not sexual spores; they are a form of vegetative propagation. They are not produced inside antheridia, which are male reproductive organs, and they do not fix nitrogen. Gemmae provide an efficient means of asexual reproduction in favourable conditions.
Q15. Assertion: Male and female gametophytes of gymnosperms are independent and free-living.
Reason: Both types of gametophytes remain within sporangia retained on sporophyte.
Correct Answer: (d)
The assertion is false because gymnosperm gametophytes are not free‑living; they are retained within the sporangia on the sporophyte. The reason is true: the male gametophyte (pollen grain) is confined within the microsporangium, and the female gametophyte develops inside the megasporangium (nucellus). The reason correctly describes their retention but the assertion contradicts this. Hence, assertion false, reason true.
Q16. Protonema stage occurs in the life cycle of:
Correct Answer: (b)
A protonema is a thread‑like, filamentous, green structure that develops directly from a moss spore. It represents the first stage of the gametophyte in mosses (e.g., Funaria). From this protonema, buds arise that develop into the leafy gametophyte. This protonemal stage is absent in liverworts like Marchantia, where the spore germinates directly into a thallus. Pteridophytes (Selaginella) and gymnosperms (Cycas) do not have a protonema stage. The protonema is a characteristic feature of the life cycle of mosses.
Q17. Match the roots with their associations:
Column-I
Column-II
A. Pinus
1. Mycorrhiza
B. Cycas
2. Coralloid roots with cyanobacteria
C. Mosses
3. Multicellular rhizoids
D. Bryophytic thalli
4. Unicellular or multicellular rhizoids
Correct Answer: (a)
Pinus forms mycorrhizal associations with fungi (1). Cycas has coralloid roots with cyanobacteria (2). Mosses have multicellular rhizoids (3). Bryophytic thalli (liverworts) have unicellular or multicellular rhizoids (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q18. Assertion: Gymnosperms are called naked-seeded plants.
Reason: Their ovules and seeds are not enclosed by any ovary wall.
Correct Answer: (a)
Gymnosperms are termed 'naked‑seeded' because their seeds develop exposed on the surface of megasporophylls (or cone scales) without being enclosed within an ovary. The reason correctly explains that the ovules and seeds lack an ovary wall, unlike angiosperms where seeds are enclosed in fruits. This exposed condition is the defining feature of gymnosperms. Thus, the reason accurately justifies the term 'naked‑seeded'.
Q19. Assertion: In bryophytes, gametophyte is haploid while sporophyte is diploid.
Reason: The sporophyte arises from zygote formed after fusion of haploid gametes.
Correct Answer: (a)
The assertion is true: the gametophyte is haploid (n) and the sporophyte is diploid (2n) in bryophytes. The reason correctly explains this: the sporophyte develops from the zygote, which is formed by the fusion of two haploid gametes (sperm and egg). This fertilisation restores the diploid chromosome number. Thus, the reason provides the genetic basis for the ploidy difference between the two generations.
Q20. The smallest angiosperm mentioned in the chapter is:
Correct Answer: (a)
Wolffia is a genus of aquatic flowering plants that are the smallest angiosperms known. They are rootless, free‑floating, and measure only a few millimetres in size. Lemna (duckweed) is also small but larger than Wolffia. Marchantia is a bryophyte (liverwort) and Chlamydomonas is a green alga, not angiosperms. Wolffia is notable for its minute size and rapid reproduction, making it an example of extreme reduction in flowering plants.
Q21. In gymnosperms, the male gametophyte is:
Correct Answer: (b)
In gymnosperms, the male gametophyte is highly reduced and consists of only a few cells encased within the pollen grain. The pollen grain is the microspore that germinates to form the male gametophyte, which produces sperms (or a pollen tube) but is not free‑living. It remains dependent on the sporophyte for nourishment. It does not develop into a photosynthetic thallus or a free‑living prothallus. This extreme reduction is an adaptation to terrestrial life, allowing reproduction without external water.
Q22. The dominant pigments of Chlorophyceae are:
Correct Answer: (c)
Chlorophyceae, or green algae, possess chlorophyll a and b as their primary photosynthetic pigments, which give them a characteristic green colour. These pigments are similar to those found in higher plants and are efficient at absorbing red and blue light. They lack chlorophyll c, d, or fucoxanthin, which are found in other algal groups. Phycoerythrin is a red pigment present in red algae and cyanobacteria. The presence of chlorophyll b along with a is a key feature that distinguishes green algae from other algal classes.
Q23. Bryophytes are called amphibians of the plant kingdom because they:
Correct Answer: (c)
Bryophytes are considered amphibians because they live on land but depend on water for their sexual reproduction. Their male gametes (antherozoids) are flagellated and must swim through water to reach the female archegonia for fertilisation. This dual requirement—terrestrial habitat but aquatic reproduction—mirrors that of amphibians in the animal kingdom. Bryophytes lack true vascular tissues and seeds, so they cannot reproduce without external water. This dependency limits their distribution to moist, shady environments.
Q24. Chemotaxonomy is most useful when:
Correct Answer: (c)
Chemotaxonomy uses the chemical composition of organisms, such as the presence of specific secondary metabolites, proteins, or DNA sequences, to clarify taxonomic relationships. When morphological characters are ambiguous or convergent, chemical data can provide decisive evidence. For example, similar-looking plants may be distinguished by their unique alkaloid or flavonoid profiles. This approach is particularly helpful in resolving classification disputes where external features are not sufficient. It complements other taxonomic methods and often reveals hidden evolutionary relationships.
Q25. The dominant generation in bryophytes is the:
Correct Answer: (b)
In bryophytes, the haploid gametophyte is the dominant, independent, and long‑lived phase of the life cycle. It is the green, photosynthetic plant body that we commonly recognise as moss or liverwort. The sporophyte, in contrast, is diploid and remains attached to and nutritionally dependent on the gametophyte. This is the reverse of the situation in higher plants, where the sporophyte is dominant. The gametophyte is the main vegetative stage, carrying out photosynthesis and reproduction.
Q26. Match the group with its water requirement status:
Column-I
Column-II
A. Algae
1. Entire life cycle in/near water
B. Bryophytes
2. Water required mainly for fertilisation
C. Pteridophytes
3. Water needed for gametophyte and fertilisation
D. Gymnosperms
4. Pollen tube carries gametes (external water not needed)
Correct Answer: (a)
Algae are aquatic throughout their life cycle (1). Bryophytes need water mainly for fertilisation (2). Pteridophytes require water for both gametophyte growth and fertilisation (3). Gymnosperms have pollen tubes, so external water is not needed (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q27. Match the sporophyll arrangement with the group:
Column-I
Column-II
A. Strobili (cones)
1. Selaginella / Equisetum
B. Sori on leaves
2. Ferns
C. Monoecious cones
3. Pinus
D. Spores in simple sporangia
4. Ulothrix
Correct Answer: (a)
Strobili (cones) occur in Selaginella and Equisetum (1). Sori (clusters of sporangia) are found on fern leaves (2). Pinus has monoecious cones (3). Ulothrix produces simple sporangia (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q28. Assertion: Bryophyte sporophyte is partially parasitic on gametophyte.
Reason: Bryophyte sporophyte is attached to the photosynthetic gametophyte and derives nourishment from it.
Correct Answer: (a)
In bryophytes, the sporophyte is permanently attached to the gametophyte and depends on it for nutrition, making it partially parasitic. The reason correctly explains this relationship: the sporophyte lacks chlorophyll and cannot photosynthesise sufficiently, so it obtains water, minerals, and organic compounds from the gametophyte. This dependency is why the sporophyte is often considered parasitic on the gametophyte, although it shares the same genetic parentage. Thus, the reason accurately justifies the assertion.
Q29. Assertion: Pollen tube in gymnosperms carries male gametes to archegonia.
Reason: After reaching ovule, pollen tube releases male gametes near mouth of archegonium.
Correct Answer: (a)
In gymnosperms, the pollen grain germinates to form a pollen tube that grows through the nucellus toward the archegonia. The reason correctly describes that the pollen tube delivers the male gametes (sperm) close to the archegonia, where fertilisation occurs. This process eliminates the need for external water for sperm transport. Both the assertion and reason are true, and the reason explains the functional role of the pollen tube.
Q30. Assertion: Artificial systems of classification may separate closely related species.
Reason: Artificial systems often rely on few superficial morphological characters.
Correct Answer: (a)
The assertion is true because artificial systems use only a limited number of traits, often superficial ones like colour or number of stamens, which may not reflect natural relationships. The reason correctly explains this: such systems focus on a few characters and ignore many other important features, leading to the grouping of unrelated species and separation of closely related ones. For example, Linnaeus's sexual system often placed dissimilar plants together. Thus, the reason is the correct explanation for why artificial systems can misclassify.
Q31. In pteridophytes, sporangia – which statements are correct? (i) Are borne on sporophylls. (ii) May be aggregated in strobili or cones in some genera. (iii) Produce spores by mitosis in spore mother cells.
Correct Answer: (a)
Sporangia are borne on sporophylls (i) and may be arranged in strobili (e.g., Selaginella) (ii). Spores are produced by meiosis, not mitosis, in spore mother cells (iii false). Thus, (i) and (ii) are correct.
Q32. Floridean starch is the reserve food material of:
Correct Answer: (c)
Floridean starch is a type of glucose polymer similar to amylopectin, found in the cytoplasm of red algae (Rhodophyceae). It serves as the main carbohydrate reserve, accumulating in the form of granules. This starch is different from the starch stored in chloroplasts of green algae and higher plants. Red algae do not store laminarin or mannitol; those are typical of brown algae. The presence of floridean starch is one of the key biochemical characteristics used to distinguish red algae from other algal groups.
Q33. Assertion: Red algae can occur at great depths in oceans.
Reason: Their pigment phycoerythrin efficiently absorbs light available in deep water.
Correct Answer: (a)
Red algae are found at greater depths than many other algae because they possess phycoerythrin, a pigment that absorbs blue‑green light, which penetrates deeper into water. The reason correctly explains that phycoerythrin enables them to utilise the available light spectrum at those depths. This adaptation allows them to photosynthesise in low‑light conditions where chlorophyll alone would be inefficient. Thus, the ability to absorb deep‑penetrating light supports their occurrence at great depths.
Q34. Assertion: Liverwort thallus is dorsiventral and closely appressed to the substrate.
Reason: Liverworts usually grow in moist shady habitats like banks of streams and damp soil.
Correct Answer: (b)
Both the assertion and the reason are true: liverworts have a dorsiventral, flattened thallus that is closely appressed to the ground, and they typically grow in moist, shaded habitats. However, the reason does not fully explain the dorsiventral shape; the dorsiventral form is an adaptation for efficient photosynthesis and water absorption in a flat, low‑growing plant. While the habitat influences the growth form, the reason is not the direct cause of the dorsiventral thallus. Therefore, both are true but the reason is not the correct explanation.
Q35. Regarding Bryophytes, which statements are correct? (i) They lack true roots, stems and leaves. (ii) Plant body is thalloid, prostrate or erect attached by rhizoids. (iii) Sporophyte is the dominant independent generation.
Correct Answer: (a)
Bryophytes lack true roots, stems, and leaves (i); they have a thalloid or erect body attached by rhizoids (ii). However, the dominant generation is the gametophyte, and the sporophyte is dependent on it, so (iii) is false. Hence, (i) and (ii) are correct.
Q36. Match the structures with the respective groups:
Column-I (Structure)
Column-II (Plant)
A. Strobilus (cone)
1. Selaginella / Equisetum
B. Gemma cup
2. Marchantia
C. Protonema
3. Funaria
D. Prothallus
4. Fern
Correct Answer: (a)
Strobili (cones) are found in Selaginella and Equisetum (1). Gemma cups are characteristic of Marchantia (2). Protonema is the first stage in moss (Funaria) (3). Prothallus is the fern gametophyte (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q37. Match the habitat/habit with the plant group:
Column-I
Column-II
A. Largely aquatic thalloid autotrophs
1. Algae
B. Moist shady terrestrial plants without true roots
2. Bryophytes
C. Cool damp terrestrial plants with vascular tissues
3. Pteridophytes
D. Seed plants with flowers
4. Angiosperms
Correct Answer: (a)
Algae are largely aquatic, thalloid autotrophs (1). Bryophytes are moist shady terrestrial plants without true roots (2). Pteridophytes are cool damp terrestrial plants with vascular tissues (3). Angiosperms are seed plants with flowers (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q38. Food in brown algae is stored mainly as:
Correct Answer: (b)
Brown algae store their photosynthetic products as complex carbohydrates, primarily laminarin (a β‑glucan) and mannitol (a sugar alcohol). These compounds are soluble and serve as both energy reserves and osmotic regulators. Starch is the main reserve in green algae, floridean starch in red algae, and glycogen in animals and fungi. The presence of laminarin and mannitol is a distinctive feature of the Phaeophyceae, helping them survive in fluctuating marine environments. These stored products are important for their metabolism during periods of low light.
Q39. Cyanobacteria are no longer considered algae mainly because they:
Correct Answer: (c)
Algae are defined as eukaryotic photosynthetic organisms, while cyanobacteria are prokaryotes. Their cells lack a nucleus and other membrane‑bound organelles, placing them in the kingdom Monera rather than Plantae. They are not strictly multicellular and they do contain chlorophyll, but of a different type. The presence of prokaryotic cell structure is the primary reason for their exclusion from algae. Modern classification recognises this fundamental difference.
Q40. In Whittaker’s five-kingdom classification, cyanobacteria were placed under:
Correct Answer: (b)
Cyanobacteria are prokaryotic organisms that lack a true nucleus and membrane‑bound organelles. In the five‑kingdom system, all prokaryotes are assigned to the kingdom Monera. Although they perform oxygenic photosynthesis, their cellular organisation is fundamentally different from that of eukaryotic algae. Historically they were grouped with algae, but modern taxonomy correctly places them in Monera based on their prokaryotic structure.
Q41. Match the life-cycle structure with its correct ploidy:
Column-I (Structure)
Column-II (Ploidy)
A. Protonema of moss
1. Haploid
B. Capsule of moss
2. Diploid
C. Prothallus of fern
3. Haploid
D. Pollen grain
4. Haploid
Correct Answer: (a)
Protonema is haploid (gametophytic) (1). The moss capsule is diploid (sporophytic) (2). Prothallus is haploid (gametophyte) (3). Pollen grain is haploid (male gametophyte) (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q42. Assertion: Green algae have pyrenoids in chloroplasts.
Reason: Pyrenoids are storage bodies containing protein besides starch.
Correct Answer: (a)
The assertion is true: pyrenoids are commonly found in the chloroplasts of green algae (Chlorophyceae). The reason is also correct: pyrenoids are proteinaceous structures where starch is synthesised and stored; they contain both protein and starch. The presence of pyrenoids is a characteristic feature of many green algae, aiding in carbohydrate metabolism. Thus, the reason correctly explains why green algae have pyrenoids—they serve as storage bodies.
Q43. In liverworts, which statements are correct? (i) Plant body is usually thalloid and dorsiventral. (ii) Asexual reproduction occurs by fragmentation and gemmae. (iii) Gemmae germinate to give sporophyte directly.
Correct Answer: (a)
Liverworts have a dorsiventral thallus (i) and reproduce asexually by fragmentation and gemmae (ii). Gemmae, however, germinate to produce new gametophytes, not sporophytes (iii is false). So only (i) and (ii) are correct.
Q44. Assertion: Cyanobacteria are no longer placed under algae in the plant kingdom.
Reason: Cyanobacteria are prokaryotic organisms belonging to Monera.
Correct Answer: (a)
The assertion is true because cyanobacteria have been excluded from algae (Plantae) in modern classification. The reason correctly explains this: cyanobacteria are prokaryotes, lacking a true nucleus and organelles, and are placed in the kingdom Monera. This cellular difference is the fundamental reason for their separate placement. Historically they were grouped with algae, but modern taxonomy recognises their distinct prokaryotic nature. Thus, the reason accurately supports the assertion.
Q45. General features of algae – which statements are correct? (i) True algae are largely autotrophic eukaryotes. (ii) They occur in fresh water, brackish water and marine habitats. (iii) They are restricted only to moist soil, never aquatic.
Correct Answer: (a)
True algae are eukaryotic autotrophs (i) and inhabit diverse aquatic environments (ii). They are not restricted to moist soil; many are aquatic, so (iii) is false. Only (i) and (ii) are correct.
Q46. Numerical taxonomy primarily differs from earlier systems because it:
Correct Answer: (d)
Numerical taxonomy, also called phenetics, converts many observable characters into numerical codes. These coded data are then processed by computer algorithms to calculate similarities between organisms. This approach assigns equal weight to all characters, removing subjective bias in classification. It can handle hundreds of traits simultaneously, making it more objective than earlier systems that relied on a few selected features. This method helps in constructing robust phylogenetic trees based on overall similarity.
Q47. Agar used in microbial culture media is obtained from:
Correct Answer: (b)
Agar is a gel‑forming polysaccharide extracted from the cell walls of certain red algae, primarily Gelidium and Gracilaria. It is widely used as a solidifying agent in microbiological culture media because it melts at about 85 °C and solidifies at around 40 °C, allowing for easy handling. Additionally, agar is resistant to degradation by most microorganisms, making it an ideal support medium. Chlorella is a green alga used as food, Sargassum and Ectocarpus are brown algae that yield algin but not agar. Therefore, the correct source is red algae.
Q48. Bryophytes in ecology – which statements are correct? (i) Often act as pioneer plants with lichens in succession. (ii) Help in soil formation by rock decomposition. (iii) Increase soil erosion by loosening soil.
Correct Answer: (a)
Bryophytes, along with lichens, are pioneers on bare rock (i) and contribute to soil formation through rock breakdown (ii). They actually reduce soil erosion by forming dense mats, so (iii) is false. Only (i) and (ii) are correct.
Q49. Match the groups with their dominant generation:
Column-I (Group)
Column-II (Dominance)
A. Algae
1. Dominant gametophyte; sporophyte dependent
B. Bryophytes
2. Dominant sporophyte; gametophyte reduced
C. Pteridophytes
3. Thalloid haploid body predominates
D. Gymnosperms
4. Highly reduced gametophyte retained on sporophyte
Correct Answer: (a)
Algae generally have a haploid thalloid body as the main phase (3). Bryophytes have a dominant gametophyte and a dependent sporophyte (1). Pteridophytes have a dominant sporophyte with a reduced gametophyte (2). Gymnosperms have a highly reduced gametophyte retained within the sporangia (4). This pattern shows the trend of sporophyte dominance in the plant kingdom. Correct matching: A‑3, B‑1, C‑2, D‑4.
Q50. Assertion: Algae significantly increase dissolved oxygen in water bodies.
Reason: Algae are chlorophyll-bearing autotrophs performing photosynthesis in aquatic habitats.
Correct Answer: (a)
The assertion is true because algae, through photosynthesis, release oxygen into the water, raising dissolved oxygen levels. The reason correctly identifies algae as photosynthetic autotrophs that use chlorophyll to capture light and fix CO₂. This photosynthetic activity is the direct cause of oxygen production. In aquatic ecosystems, algae are the major oxygen producers, supporting aquatic life. Therefore, the reason is the correct explanation for the assertion.
Q51. Match the algal classes with their stored food:
Column-I (Class)
Column-II (Stored Food)
A. Chlorophyceae
1. Mannitol and laminarin
B. Phaeophyceae
2. Floridean starch
C. Rhodophyceae
3. Starch in pyrenoids
Correct Answer: (a)
Chlorophyceae store starch, often in association with pyrenoids (3). Phaeophyceae store laminarin and mannitol (1). Rhodophyceae store floridean starch (2). These storage products are unique to each group and are used in taxonomy. Thus, the correct pairing is A‑3, B‑1, C‑2.
Q52. Assertion: Dicots and monocots are the two major classes of angiosperms.
Reason: They differ chiefly in number of cotyledons in the embryo.
Correct Answer: (a)
The assertion is correct: angiosperms are broadly classified into dicots (dicotyledons) and monocots (monocotyledons). The reason correctly identifies the primary distinguishing feature: the number of cotyledons (seed leaves) in the embryo—two in dicots and one in monocots. This difference is fundamental and influences many other morphological traits. Thus, the reason explains the basis of this classification.
Q53. The chief storage product in Chlorophyceae is:
Correct Answer: (c)
Green algae (Chlorophyceae) store their photosynthetic products as starch, which is often associated with pyrenoids—specialised proteinaceous structures within the chloroplasts. Pyrenoids act as centres for starch synthesis and accumulation. In contrast, brown algae store laminarin and mannitol, while red algae store floridean starch. The presence of starch as the main reserve carbohydrate is a hallmark of the Chlorophyceae and reflects their evolutionary link with higher plants, which also store starch. This storage form is readily metabolised when energy is needed.
Q54. Match the spore type with the representative plants:
Column-I (Spore Type)
Column-II (Plants)
A. Homosporous plants
1. Most pteridophytes
B. Heterosporous plants
2. Selaginella and 3. Salvinia
Correct Answer: (a)
Most pteridophytes (e.g., ferns, Equisetum) are homosporous, producing one type of spore (1). Selaginella and Salvinia are heterosporous, producing microspores and megaspores (2 and 3). Thus, the correct matching is A‑1, B‑(2 and 3).
Q55. Regarding economic importance, which are correct? (i) Sphagnum provides peat and packing material. (ii) Many red and brown algae serve as human food. (iii) Gymnosperms include the tallest trees such as Sequoia.
Correct Answer: (d)
All three statements are correct. Sphagnum moss is used as fuel (peat) and packaging. Red algae (e.g., Porphyra) and brown algae (e.g., Laminaria) are edible. Sequoia, a gymnosperm, is one of the tallest trees. These are well‑known examples of economic importance.
Q56. Heterospory is exhibited in pteridophytes such as:
Correct Answer: (b)
Heterospory is the production of two distinct types of spores—microspores (male) and megaspores (female)—in the same plant. Among pteridophytes, this is seen in Selaginella and Salvinia, which are heterosporous. Lycopodium, Equisetum, Psilotum, Adiantum, and Dryopteris are homosporous, producing only one type of spore. Heterospory is considered an important evolutionary step because it led to the development of seeds. The retention of megaspores on the parent sporophyte gave rise to the seed habit.
Q57. Assertion: Algae show all three types of sexual reproduction: isogamy, anisogamy and oogamy.
Reason: In Ulothrix, Eudorina and Volvox, these different types of gamete fusion are observed.
Correct Answer: (a)
Algae exhibit a wide range of sexual reproduction, including isogamy (fusion of morphologically similar gametes), anisogamy (fusion of dissimilar gametes in size), and oogamy (fusion of a large non‑motile egg with a small motile sperm). The reason correctly provides examples: Ulothrix shows isogamy, Eudorina anisogamy, and Volvox oogamy. Thus, the reason supports the assertion by giving representative organisms for each type.
Q58. Assertion: Spread of living pteridophytes is restricted geographically.
Reason: Their gametophytes require cool, damp, shady places and water for fertilisation.
Correct Answer: (a)
Pteridophytes are not as widespread as seed plants because their gametophytes are small and delicate, needing moist, shaded habitats. The reason correctly explains this: they require water for the motile antherozoids to swim to the archegonia, and the gametophyte itself is susceptible to drying. This dependence on moisture limits their distribution to cool, damp areas. Thus, the restriction in spread is directly due to these reproductive and environmental requirements.
Q59. About gymnosperm gametophytes, which statements are correct? (i) Male gametophyte is reduced and confined within pollen grain. (ii) Female gametophyte develops within megasporangium from megaspore. (iii) Both gametophytes are free-living and photosynthetic.
Correct Answer: (a)
The male gametophyte is reduced and housed within the pollen grain (i). The female gametophyte develops inside the megasporangium from a megaspore (ii). However, gymnosperm gametophytes are not free‑living; they are retained on the sporophyte (iii false). Therefore, (i) and (ii) are correct.
Q60. Assertion: Numerical taxonomy can handle hundreds of characters in classification.
Reason: In numerical taxonomy, characters are coded and processed using computers.
Correct Answer: (a)
Numerical taxonomy is designed to handle large data sets by converting morphological, biochemical, and other characters into numerical codes. These codes are then analysed by computer algorithms to compute similarity coefficients and construct dendrograms. The large number of characters—often hundreds—can be processed efficiently because of computer power. The reason correctly explains that coding and computer processing allow this method to manage extensive data. Hence, the assertion and reason are both true and correctly linked.
Q61. In brown algae, which statements are correct? (i) Vegetative cells have cellulose wall with outer gelatinous algin. (ii) Asexual reproduction occurs by biflagellate pear-shaped zoospores. (iii) Gametes are non-flagellate and non-motile.
Correct Answer: (a)
Brown algae have cell walls containing cellulose and an outer gelatinous layer of algin (i). Asexual reproduction is often by pear‑shaped biflagellate zoospores (ii). However, gametes in brown algae are also flagellated (motile), so statement (iii) is incorrect. Therefore, only (i) and (ii) are correct.
Q62. Primary producers in aquatic ecosystems are predominantly:
Correct Answer: (c)
Algae form the base of aquatic food webs by converting sunlight into chemical energy through photosynthesis. They are abundant in oceans, lakes, and rivers, serving as the main food source for zooplankton and other aquatic consumers. Unlike bryophytes or pteridophytes, which are primarily terrestrial, algae are specially adapted to live and reproduce in water. Their rapid growth and high photosynthetic efficiency make them the dominant primary producers in marine and freshwater ecosystems. Without algae, most aquatic life would not survive.
Q63. Heterospory – which statements are correct? (i) Involves production of two sizes of spores. (ii) Is shown by Selaginella and Salvinia. (iii) Has no evolutionary relation with seed habit.
Correct Answer: (a)
Heterospory produces two types of spores (microspores and megaspores) (i) and is seen in Selaginella and Salvinia (ii). It is considered a precursor to the seed habit, so (iii) is false. Therefore, (i) and (ii) are correct.
Q64. Angiosperms – which statements are correct? (i) Produce pollen grains and ovules in flowers. (ii) Enclose seeds within fruits. (iii) Do not produce any economically important products.
Correct Answer: (a)
Angiosperms produce pollen and ovules inside flowers (i) and their seeds are enclosed in fruits (ii). They are of immense economic importance (food, medicines, timber, etc.), so (iii) is false. Hence, only (i) and (ii) are correct.
Q65. Match the plant groups with economic products:
Column-I (Plant)
Column-II (Product)
A. Sphagnum
1. Peat, packing material
B. Brown algae
2. Algin
C. Red algae
3. Agar, carrageenan
D. Chlorella
4. Protein-rich food supplement
Correct Answer: (a)
Sphagnum (moss) provides peat and is used as a packing material (1). Brown algae yield algin (2). Red algae are sources of agar and carrageenan (3). Chlorella is a protein‑rich food supplement (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q66. Features of conifer leaves – which statements are correct? (i) Needle-like leaves reduce surface area. (ii) Thick cuticle reduces water loss. (iii) Sunken stomata increase transpiration.
Correct Answer: (a)
Conifers have needle‑like leaves to reduce surface area (i) and a thick cuticle to minimise water loss (ii). Sunken stomata reduce transpiration, not increase it, so (iii) is false. Therefore, (i) and (ii) are correct.
Q67. In pteridophytes, the main plant body is:
Correct Answer: (b)
Pteridophytes have a dominant diploid sporophyte that is differentiated into true roots, stems, and leaves. This sporophyte is the conspicuous, independent plant we observe. The gametophyte is small, often heart‑shaped (prothallus), and independent but short‑lived. In contrast, bryophytes have a dominant gametophyte. The sporophyte of pteridophytes is well‑developed with vascular tissues (xylem and phloem), enabling them to grow larger than bryophytes. This pattern of sporophyte dominance is a step towards the seed plants.
Q68. Algal reproduction – which statements are correct? (i) Vegetative reproduction occurs by fragmentation. (ii) Asexual reproduction commonly occurs via zoospores. (iii) Sexual reproduction is exclusively oogamous.
Correct Answer: (a)
Algae reproduce vegetatively by fragmentation (i) and asexually by zoospores (ii). Sexual reproduction includes isogamy, anisogamy, and oogamy, not exclusively oogamy, so (iii) is false. Thus, only (i) and (ii) are correct.
Q69. Match the life-cycle events with the groups:
Column-I
Column-II
A. Zygote undergoes meiosis immediately
1. Many algae
B. Zygote forms sporophyte dependent on gametophyte
2. Bryophyte
C. Zygote develops into independent sporophyte with seeds
3. Gymnosperm
D. Zygote forms sporophyte with a prothallus stage
4. Pteridophyte
Correct Answer: (a)
In many algae, the zygote directly undergoes meiosis to produce spores (1). In bryophytes, the zygote gives rise to a sporophyte that is dependent on the gametophyte (2). In gymnosperms, the zygote develops into an independent sporophyte and forms seeds (3). In pteridophytes, the zygote forms a sporophyte that goes through a prothallus stage (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q70. Match the groups with vascular tissue status:
Column-I
Column-II
A. Algae
1. No true vascular tissue
B. Bryophytes
2. First land plants with xylem and phloem
C. Pteridophytes
3. Well-developed vascular system with naked seeds
D. Gymnosperms
4. Mostly aquatic thalloid without vascular tissue
Correct Answer: (a)
Algae are mostly aquatic and lack vascular tissue (4). Bryophytes have no true vascular tissue (1). Pteridophytes are the first land plants with xylem and phloem (2). Gymnosperms have a well‑developed vascular system and bear naked seeds (3). Correct matching: A‑4, B‑1, C‑2, D‑3.
Q71. Assertion: Mosses and lichens are pioneer colonisers on bare rocks.
Reason: They help in rock decomposition and soil formation.
Correct Answer: (a)
Mosses and lichens are among the first organisms to colonise bare rock surfaces. The reason correctly states that they contribute to rock decomposition through physical and chemical weathering, gradually forming soil. Their growth retains moisture and organic matter, facilitating the establishment of other plants. This pioneer role is ecologically important in primary succession. Thus, the reason explains why they are considered pioneers.
Q72. Assertion: In moss, protonema develops directly from a spore.
Reason: Protonema is the first creeping, filamentous, green stage of moss gametophyte.
Correct Answer: (a)
The assertion is true: when a moss spore germinates, it produces a filamentous structure called a protonema. The reason correctly defines the protonema as the initial, green, creeping stage of the gametophyte. This protonema later gives rise to buds that develop into the leafy shoot. Thus, the reason explains that the protonema arises from the spore and is the first visible gametophytic stage. Both are correct and causally linked.
Q73. Gametophyte of pteridophytes (prothallus) – which statements are correct? (i) It is generally small, multicellular and photosynthetic. (ii) It requires cool, damp, shady places. (iii) It bears flowers and fruits.
Correct Answer: (a)
The prothallus is small, multicellular, photosynthetic (i) and needs moist, shady conditions (ii). Pteridophytes are cryptogams and do not produce flowers or fruits (iii false). Hence, (i) and (ii) are correct.
Q74. In red algae, which statements are correct? (i) Majority are marine, often in warmer waters. (ii) Sexual reproduction involves non-motile gametes and complex post-fertilisation development. (iii) Food is stored as laminarin.
Correct Answer: (a)
Most red algae are marine and often found in warmer waters (i). Their sexual reproduction involves non‑motile gametes and a complex post‑fertilisation development, often with a carposporophyte (ii). However, their stored food is floridean starch, not laminarin (which is found in brown algae). So (iii) is false. Thus, only (i) and (ii) are correct.
Q75. The heart-shaped thalloid gametophyte of ferns is known as:
Correct Answer: (b)
The gametophyte of ferns is a small, thin, heart‑shaped structure called a prothallus. It is photosynthetic, bears rhizoids for anchorage, and produces male (antheridia) and female (archegonia) sex organs. The prothallus is the free‑living haploid generation that arises from a spore. Protonema is the filamentous stage found in mosses, not ferns. Archegonium is the female sex organ, and sporophyll is a leaf that bears sporangia. Thus, prothallus is the correct term for the fern gametophyte.
Q76. Regarding Chlorophyceae, which statements are correct? (i) Plant body may be unicellular, colonial or filamentous. (ii) Cell wall has inner layer of cellulose and outer of pectose. (iii) Chloroplasts may be discoid, cup-shaped, spiral or ribbon-shaped.
Correct Answer: (d)
All three statements accurately describe Chlorophyceae. They exhibit diverse forms: unicellular (Chlamydomonas), colonial (Volvox), or filamentous (Spirogyra). Their cell wall is composed of cellulose and pectose, with inner cellulose and outer pectose layers. Chloroplasts vary in shape, including discoid, cup‑shaped, spiral, and ribbon‑like. These features are characteristic of green algae and are well‑documented in plant taxonomy.
Q77. Assertion: Moss sporophyte is more elaborate than liverwort sporophyte.
Reason: Moss sporophyte bears foot, seta and capsule and shows an elaborate spore dispersal mechanism.
Correct Answer: (a)
Moss sporophytes are structurally more complex than those of liverworts. They consist of a foot (anchoring), a seta (stalk), and a capsule (sporangium) with a peristome for spore dispersal. The reason correctly enumerates these parts and highlights the elaborate dispersal mechanism, which is lacking in the simpler liverwort sporophyte. Thus, the reason explains why the moss sporophyte is considered more elaborate.
Q78. Red algae distribution – which statements are correct? (i) Many species occur in warm marine waters. (ii) They can inhabit both well-lit shallow regions and deep waters. (iii) All are strictly freshwater.
Correct Answer: (a)
Most red algae are marine and often in warmer waters (i). They can grow in shallow as well as deep waters, thanks to phycoerythrin (ii). They are not all freshwater; the majority are marine, so (iii) is false. Only (i) and (ii) are correct.
Q79. Match the gymnosperm feature with the respective genus:
Column-I (Feature)
Column-II (Genus)
A. Unbranched stem
1. Cycas
B. Branched stem; mycorrhiza
2. Pinus
C. Dwarf and long shoots
3. Ginkgo
D. Coralloid roots
4. Cycas
Correct Answer: (a)
Cycas has an unbranched stem (1). Pinus has a branched stem and forms mycorrhiza (2). Ginkgo has dwarf and long shoots (3). Coralloid roots are also found in Cycas (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q80. Assertion: Brown algae vary in colour from olive green to brown.
Reason: Variation in amount of fucoxanthin determines their colour.
Correct Answer: (a)
Brown algae (Phaeophyceae) exhibit a range of colours from olive‑green to dark brown depending on the relative amounts of fucoxanthin (a brownish pigment) and chlorophyll. The reason correctly states that variation in fucoxanthin content is responsible for this colour range. When fucoxanthin is abundant, the algae appear brown; when less, they look greener. This pigment masks the green chlorophyll and gives the characteristic brown hue. Thus, the reason accurately explains the colour variation.
Q81. Match the reproductive propagule with its respective group:
Column-I (Propagule)
Column-II (Group)
A. Zoospore
1. Algae (asexual)
B. Gemma
2. Liverwort (asexual)
C. Non-motile spore
3. Rhodophyceae (asexual)
D. Microspore
4. Gymnosperm
Correct Answer: (a)
Zoospores are common asexual reproductive units in algae (1). Gemmae are asexual buds in liverworts (2). Non‑motile spores are found in red algae (Rhodophyceae) (3). Microspores are produced in gymnosperms (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q82. Assertion: Pteridophytes are the first vascular land plants.
Reason: They possess xylem and phloem in true roots, stems and leaves.
Correct Answer: (a)
The assertion is correct: pteridophytes were the earliest plants to evolve a well‑developed vascular system (xylem and phloem), allowing them to grow tall and colonise land effectively. The reason correctly states that they have true vascular tissues in their roots, stems, and leaves. This vascularisation is what distinguishes them from bryophytes and gives them the status of the first vascular land plants. Thus, the reason explains the assertion.
Q83. Moss sporophyte – which statements are correct? (i) Comprises foot, seta and capsule. (ii) Is more elaborate than liverwort sporophyte. (iii) Capsule contains spores formed after meiosis.
Correct Answer: (d)
All three statements are true. Moss sporophytes have a foot, seta, and capsule (i). They are structurally more complex than those of liverworts (ii). The capsule undergoes meiosis to produce spores (iii). These features are characteristic of mosses.
Q84. Pteridophytes – which statements are correct? (i) Sporophyte is differentiated into true root, stem and leaves. (ii) Water is required for transfer of antherozoids to archegonium. (iii) Roots lack vascular tissue.
Correct Answer: (a)
Pteridophytes have a sporophyte with true roots, stems, and leaves (i). They require water for the motile antherozoids to reach the archegonia (ii). However, their roots do have vascular tissue (xylem and phloem), so (iii) is false. Thus, only (i) and (ii) are correct.
Q85. Assertion: Angiosperms have flowers as reproductive structures.
Reason: In angiosperms, pollen grains and ovules are produced in specialised structures called flowers.
Correct Answer: (a)
Angiosperms are defined by the presence of flowers, which are reproductive shoots bearing modified leaves. The reason correctly states that flowers contain the male and female reproductive structures—pollen grains and ovules—within them. This organisation is unique to angiosperms and distinguishes them from gymnosperms, which have cones. Thus, the reason explains why flowers are the characteristic reproductive organs of angiosperms.
Q86. Match the forms with their respective features:
Column-I
Column-II
A. Kelps
1. Unicellular alga, food supplement
B. Chlorella
2. Marine brown alga used as food
C. Laminaria
3. Massive marine plant bodies
D. Sargassum
4. Brown alga producing algin
Correct Answer: (a)
Kelps are massive brown algae that form underwater forests (3). Chlorella is a unicellular green alga used as a food supplement (1). Laminaria is a brown alga harvested for food (2). Sargassum is a brown alga that yields algin (4). The correct matching is A‑3, B‑1, C‑2, D‑4.
Q87. Half of the total carbon dioxide fixation on earth is attributed largely to:
Correct Answer: (c)
Algae, both microscopic phytoplankton and larger seaweeds, are responsible for approximately 50% of global photosynthetic carbon fixation. They thrive in oceans, freshwater bodies, and moist terrestrial habitats, converting atmospheric CO₂ into organic matter. Their vast biomass and rapid growth rates make them a major carbon sink. This immense photosynthetic activity also contributes significantly to atmospheric oxygen production. While terrestrial plants also fix carbon, the sheer volume of algal photosynthesis in aquatic environments makes them the dominant contributors.
Q88. Assertion: Some gymnosperm roots form mycorrhiza.
Reason: In Pinus, roots show association with fungi forming mycorrhiza.
Correct Answer: (a)
Mycorrhizal associations are common in gymnosperms, and Pinus is a classic example. The reason correctly cites Pinus as a genus where roots form symbiotic relationships with fungi. These fungi help the plant absorb water and minerals, especially phosphorus, in exchange for carbohydrates. Thus, the reason provides a specific example that supports the general assertion that some gymnosperms form mycorrhizae.
Q89. Match the plant body with its feature:
Column-I
Column-II
A. Liverwort
1. Dorsiventral thallus, gemma cups
B. Moss
2. Upright leafy axes from protonema
C. Fern
3. Dorsiventral thallus of liverwort
D. Marchantia
4. Sporophyte with macrophylls
Correct Answer: (a)
Liverworts are characterised by a dorsiventral thallus (3). Mosses have an upright leafy shoot arising from a protonema (2). Ferns have a sporophyte with large leaves (macrophylls) (4). Marchantia (a liverwort) has gemma cups on its thallus (1). Correct matching: A‑3, B‑2, C‑4, D‑1.
Q90. Match the algae with the type of gamete fusion:
Column-I (Alga)
Column-II (Fusion Type)
A. Ulothrix
1. Isogamous
B. Spirogyra
2. Isogamous
C. Eudorina
3. Anisogamous
D. Volvox
4. Oogamous
Correct Answer: (a)
Ulothrix exhibits isogamous fusion (1). Spirogyra also is isogamous (2). Eudorina shows anisogamous fusion (3). Volvox is oogamous (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q91. About classification systems, which are correct? (i) Artificial systems give equal weightage to vegetative and sexual characters. (ii) Natural systems consider internal and external features. (iii) Phylogenetic systems assume taxa share a common ancestor.
Correct Answer: (c)
Artificial systems typically rely on a few superficial characters, often giving more weight to sexual features (like Linnaeus's system), so statement (i) is false. Natural systems do use many internal and external features (ii). Phylogenetic systems are based on evolutionary relationships and common ancestry (iii). Thus, only (ii) and (iii) are correct.
Q92. Numerical taxonomy – which statements are correct? (i) Uses codes for numerous characters. (ii) Each character is given equal importance. (iii) Uses only chromosome number as a character.
Correct Answer: (a)
Numerical taxonomy codes many characters (i) and assigns equal weight to each (ii). Using only chromosome number defines cytotaxonomy, not numerical taxonomy, so (iii) is false. Hence, (i) and (ii) are correct.
Q93. Coralloid roots with nitrogen-fixing cyanobacteria are characteristic of:
Correct Answer: (b)
Cycas, a gymnosperm, possesses special roots called coralloid roots that grow upward and are associated with nitrogen‑fixing cyanobacteria (e.g., Anabaena cycadeae). These roots have a symbiotic relationship with the cyanobacteria, which convert atmospheric nitrogen into usable compounds for the plant. Pinus has mycorrhizal associations but not coralloid roots. Funaria is a moss, and Selaginella is a pteridophyte, neither of which produce coralloid roots. This feature is unique to Cycas among gymnosperms.
Q94. Match the taxa with their reproductive structures:
Column-I
Column-II
A. Bryophytes
1. Flowers
B. Pteridophytes
2. Archegonia and antheridia on prothallus
C. Gymnosperms
3. Archegonia on gametophyte with biflagellate antherozoids
D. Angiosperms
4. Archegonia in ovules; pollen grains as male gametophyte
Correct Answer: (a)
Bryophytes have archegonia and antheridia on the gametophyte, with biflagellate sperms (3). Pteridophytes have archegonia and antheridia on the prothallus (2). Gymnosperms have archegonia in ovules and pollen grains as male gametophytes (4). Angiosperms have flowers as reproductive structures (1). Correct matching: A‑3, B‑2, C‑4, D‑1.
Q95. Assertion: Natural classification systems emphasise overall affinities among organisms.
Reason: These systems consider external morphology, anatomy, embryology and phytochemistry.
Correct Answer: (a)
Natural classification aims to group organisms based on their overall similarity and evolutionary relationships. The reason correctly states that these systems use a wide array of characters, including external morphology, internal anatomy, embryology, and biochemical features. By considering many traits, natural systems reveal genuine affinities and avoid the pitfalls of artificial systems. Thus, the reason explains why natural classifications are more comprehensive and accurate.
Q96. Match the classification approach with its basis:
Column-I
Column-II
A. Artificial system
1. Few gross morphological features
B. Natural system
2. Natural affinities using many features
C. Phylogenetic system
3. Evolutionary relationships
D. Numerical taxonomy
4. Computer-based coding of characters
Correct Answer: (a)
Artificial systems rely on a few superficial traits (1). Natural systems use many characters to reflect natural affinities (2). Phylogenetic systems are based on evolutionary relationships (3). Numerical taxonomy uses computer coding of characters (4). Correct matching: A‑1, B‑2, C‑3, D‑4.
Q97. Assertion: Heterospory in Selaginella is considered a precursor to seed habit.
Reason: Female gametophytes develop within megaspores retained on parent sporophyte where zygote and embryo develop.
Correct Answer: (a)
Heterospory is a key evolutionary step toward the seed habit, and Selaginella exhibits this. The reason correctly describes that the megaspore (female) is retained on the parent sporophyte, and the female gametophyte develops inside it. The zygote and later the embryo also develop within this protected environment, similar to how seeds form. This retention and nourishment of the developing embryo is the basis for seed evolution. Thus, the reason explains why heterospory is considered a precursor.
Q98. Considering algae in general, which statements are correct? (i) They fix a large fraction of global carbon dioxide. (ii) They serve as primary producers in aquatic food chains. (iii) None of them are useful as human food.
Correct Answer: (a)
Algae are major contributors to global carbon fixation (i) and are the primary producers in aquatic ecosystems (ii). However, many algae are used as human food (e.g., Porphyra, Laminaria, Chlorella), so statement (iii) is false. Thus, only (i) and (ii) are correct.
Q99. Chlorella is especially significant because it:
Correct Answer: (b)
Chlorella is a unicellular green alga that is rich in proteins, vitamins, and essential fatty acids. Its high nutritional value and ease of cultivation have made it a candidate for use as a food supplement, even for astronauts on space missions. It does not fix nitrogen; nitrogen fixation is performed by certain bacteria and cyanobacteria. Chlorella does not produce algin or peat. Its ability to be grown in controlled environments and its rapid reproduction make it a sustainable protein source. Thus, its significance lies in its potential as a nutrient‑dense food.
Q100. Match the organisms with their respective groups:
Column-I (Organism)
Column-II (Group)
A. Chlamydomonas
1. Bryophyte
B. Funaria
2. Alga
C. Selaginella
3. Pteridophyte
D. Cycas
4. Gymnosperm
Correct Answer: (a)
Chlamydomonas is a unicellular green alga (2). Funaria is a moss, a bryophyte (1). Selaginella is a pteridophyte (3). Cycas is a gymnosperm (4). This classification is based on standard taxonomic hierarchy. The correct matching is A‑2, B‑1, C‑3, D‑4.