- Which algal group exhibits the most complex thallus organization?
(a) Chlorophyceae
(b) Phaeophyceae
(c) Rhodophyceae
(d) Cyanophyceae
Answer: (b) Phaeophyceae
Explanation: Brown algae (Phaeophyceae) show the highest structural complexity, with differentiated parts such as holdfast (attachment), stipe (stem-like), and blade (leaf-like). - Agar, a phycocolloid, is derived from:
(a) Green algae
(b) Brown algae
(c) Red algae
(d) Diatoms
Answer: (c) Red algae
Explanation: Agar is a gelatinous substance obtained from red algae, mainly Gelidium and Gracilaria. It is widely used in microbiology and food industries. - Diatomite (Kieselguhr) is commercially important due to its use in:
(a) Food thickeners
(b) Fertilizers
(c) Filters and abrasives
(d) Iodine extraction
Answer: (c) Filters and abrasives
Explanation: Diatomite is composed of fossilized silica shells of diatoms and is used in water filters, polishing agents, and as insulation material. - Laminarin, a storage polysaccharide, is found in:
(a) Chlorella
(b) Laminaria
(c) Porphyra
(d) Spirogyra
Answer: (b) Laminaria
Explanation: Laminaria (a brown alga) stores food in the form of laminarin, a β-glucan polysaccharide. - Which alga is a rich source of iodine?
(a) Ulva
(b) Chlorella
(c) Sargassum
(d) Nostoc
Answer: (c) Sargassum
Explanation: Brown algae like Sargassum and Laminaria accumulate iodine from seawater and are used in iodine extraction. - Alginates, used in textiles and dentistry, are obtained from:
(a) Red algae
(b) Green algae
(c) Blue-green algae
(d) Brown algae
Answer: (d) Brown algae
Explanation: Alginic acid, a polysaccharide used as a stabilizer and emulsifier, is obtained from brown algae such as Macrocystis, Fucus, and Sargassum. - Which algal form has a coenocytic thallus structure?
(a) Volvox
(b) Ulothrix
(c) Vaucheria
(d) Chara
Answer: (c) Vaucheria
Explanation: Vaucheria (Xanthophyceae) has a siphonaceous (coenocytic) thallus with multinucleate cells lacking septa. - Nostoc is used as a biofertilizer due to its ability to:
(a) Produce growth hormones
(b) Fix atmospheric nitrogen
(c) Increase soil aeration
(d) Prevent soil erosion
Answer: (b) Fix atmospheric nitrogen
Explanation: Nostoc, a cyanobacterium, contains heterocysts for nitrogen fixation, improving soil fertility, especially in rice fields. - Which alga is commonly consumed as “Nori” in Japan?
(a) Ulva
(b) Porphyra
(c) Spirogyra
(d) Chlorella
Answer: (b) Porphyra
Explanation: Porphyra, a red alga, is dried and processed into Nori sheets, commonly used in sushi. - Carrageenan, a stabilizer in dairy products, comes from:
(a) Diatoms
(b) Green algae
(c) Red algae
(d) Brown algae
Answer: (c) Red algae
Explanation: Carrageenan is extracted from red algae such as Chondrus crispus and is used as a gelling and thickening agent in foods and cosmetics. - The unicellular motile thallus is characteristic of:
(a) Chlamydomonas
(b) Ulva
(c) Polysiphonia
(d) Ectocarpus
Answer: (a) Chlamydomonas
Explanation: Chlamydomonas is a unicellular green alga with flagella enabling motility. - Which alga is used as fodder for livestock?
(a) Chlorella
(b) Laminaria
(c) Fucus
(d) Spirulina
Answer: (b) Laminaria
Explanation: Laminaria (kelp) is used as cattle feed due to its high mineral and fiber content. - The thallus of Ulva is:
(a) Unicellular
(b) Filamentous
(c) Parenchymatous
(d) Siphonous
Answer: (c) Parenchymatous
Explanation: Ulva has a flat, sheet-like, two-cell thick parenchymatous thallus. - Phycobilins are photosynthetic pigments in:
(a) Rhodophyceae and Cyanophyceae
(b) Chlorophyceae only
(c) Phaeophyceae only
(d) Bacillariophyceae
Answer: (a) Rhodophyceae and Cyanophyceae
Explanation: Phycobilins (e.g., phycoerythrin, phycocyanin) are water-soluble accessory pigments found in red algae and cyanobacteria. - Diatomaceous earth is formed by the accumulation of:
(a) Calcium carbonate
(b) Silica
(c) Chitin
(d) Algin
Answer: (b) Silica
Explanation: Diatomaceous earth (kieselguhr) consists of silica-based frustules (shells) of fossilized diatoms. - Which alga exhibits a colonial thallus with fixed cell numbers?
(a) Chlorella
(b) Volvox
(c) Spirogyra
(d) Oscillatoria
Answer: (b) Volvox
Explanation: Volvox forms colonies of specific cell numbers, with coordinated movement and division of labor among cells. - Chlorella is used in space research because it:
(a) Produces antibiotics
(b) Grows rapidly and releases O₂
(c) Fixes nitrogen
(d) Forms biofuel
Answer: (b) Grows rapidly and releases O₂
Explanation: Chlorella is rich in chlorophyll and used in closed ecological systems for oxygen generation and food in space missions. - Kelps belong to the class:
(a) Chlorophyceae
(b) Rhodophyceae
(c) Phaeophyceae
(d) Cyanophyceae
Answer: (c) Phaeophyceae
Explanation: Kelps are large brown algae (e.g., Macrocystis, Laminaria) that form marine forests. - Which alga is a source of hydrocolloid used in microbiology?
(a) Chondrus
(b) Polysiphonia
(c) Porphyra
(d) Gracilaria
Answer: (d) Gracilaria
Explanation: Gracilaria is a red alga widely used to extract agar for microbial culture media. - The giant alga Macrocystis reaches lengths up to:
(a) 10 meters
(b) 30 meters
(c) 60 meters
(d) 100 meters
Answer: (c) 60 meters
Explanation: Macrocystis pyrifera can grow over 60 meters in length, forming dense kelp forests in cold ocean waters. - Which is NOT a product from algae?
(a) Agar
(b) Carrageenan
(c) Chitin
(d) Algin
Answer: (c) Chitin
Explanation: Chitin is a structural polysaccharide found in fungi and arthropods, not algae. - The filamentous thallus with ladder-like conjugation is seen in:
(a) Chlamydomonas
(b) Spirogyra
(c) Ulothrix
(d) Oedogonium
Answer: (b) Spirogyra
Explanation: Spirogyra undergoes scalariform conjugation, resembling a ladder during sexual reproduction. - Spirulina is promoted as a “superfood” due to its high content of:
(a) Carbohydrates
(b) Proteins
(c) Lipids
(d) Silica
Answer: (b) Proteins
Explanation: Spirulina is a cyanobacterium that contains about 60–70% protein and is used as a dietary supplement. - Which alga has a diplontic life cycle?
(a) Ulva
(b) Fucus
(c) Polysiphonia
(d) Ectocarpus
Answer: (b) Fucus
Explanation: In Fucus, the diploid sporophyte dominates, and gametes are the only haploid cells, indicating a diplontic life cycle. - The primary pigment responsible for red color in Rhodophyceae is:
(a) Fucoxanthin
(b) Chlorophyll-b
(c) Phycoerythrin
(d) Lutein
Answer: (c) Phycoerythrin
Explanation: Phycoerythrin, a phycobilin pigment, imparts a red color by absorbing blue-green wavelengths and reflecting red light. - Which alga is used to treat goiter?
(a) Chlorella
(b) Gracilaria
(c) Laminaria
(d) Chara
Answer: (c) Laminaria
Explanation: Due to its high iodine content, Laminaria is used in the treatment of iodine deficiency and related thyroid disorders. - The thallus in Chara is:
(a) Unicellular
(b) Filamentous with nodes and internodes
(c) Parenchymatous
(d) Siphonous
Answer: (b) Filamentous with nodes and internodes
Explanation: Chara (stonewort) has a branched filamentous structure resembling higher plant morphology. - Alginates are used to make:
(a) Ice cream
(b) Glass
(c) Plastic
(d) Paper
Answer: (a) Ice cream
Explanation: Alginates act as stabilizers in ice cream to prevent ice crystal formation and improve texture. - Which algal group produces neurotoxins causing shellfish poisoning?
(a) Dinoflagellates
(b) Diatoms
(c) Euglenoids
(d) Green algae
Answer: (a) Dinoflagellates
Explanation: Dinoflagellates like Gonyaulax and Alexandrium produce saxitoxins causing red tides and paralytic shellfish poisoning. - The “sea palm” (Postelsia) is a member of:
(a) Chlorophyceae
(b) Rhodophyceae
(c) Phaeophyceae
(d) Cyanophyceae
Answer: (c) Phaeophyceae
Explanation: Postelsia palmaeformis, called “sea palm”, is a brown alga resembling a miniature palm tree and found along the Pacific coast.
FUNGI: Structure of cell wall, mycelium, spore forms reproduction types: Homo-and heretrohallism, Parasexuality. Economic importance.
- The primary structural component of fungal cell walls is:
(b) Chitin (a) Cellulose
(d) Hemicellulose (c) Peptidoglycan
Answer: (b) Chitin
Explanation: Fungal cell walls are composed primarily of chitin, a polymer of N-acetylglucosamine. This provides rigidity and protection. In contrast, cellulose is found in plant cell walls and peptidoglycan in bacterial walls. - Coenocytic mycelium lacks:
(b) Cytoplasm (a) Nuclei
(d) Cell membrane (c) Septa
Answer: (c) Septa
Explanation: Coenocytic mycelium, found in lower fungi like Mucor, is multinucleate and aseptate, allowing cytoplasm to flow freely without cross walls. - Heterothallism in fungi refers to:
(a) Self-fertile mycelium
(b) Requirement of two compatible mating types
(c) Asexual reproduction only
(d) Formation of dikaryotic spores
Answer: (b) Requirement of two compatible mating types
Explanation: In heterothallic fungi, two different but compatible hyphae (+ and – strains) must come together for sexual reproduction. - Parasexuality is characterized by:
(a) Meiotic recombination
(b) Mitotic recombination without meiosis
(d) Binary fission (c) Formation of zygospores
Answer: (b) Mitotic recombination without meiosis
Explanation: Discovered in Aspergillus, parasexuality involves genetic recombination and haploidization during mitosis, bypassing the conventional meiosis pathway. - Which fungus produces aflatoxins, a potent carcinogen?
(b) Aspergillus flavus (a) Penicillium notatum
(d) Mucor mucedo (c) Saccharomyces cerevisiae
Answer: (b) Aspergillus flavus
Explanation: Aspergillus flavus infects crops like peanuts and produces aflatoxins, which are among the most dangerous natural carcinogens, affecting liver function. - The asexual spores produced in Penicillium are called:
(b) Ascospores (a) Zoospores
(d) Basidiospores (c) Conidia
Answer: (c) Conidia
Explanation: Penicillium reproduces asexually via conidia, which are borne externally on specialized hyphae called conidiophores. - In fungi, the dikaryotic phase is prominent in:
(a) Zygomycetes
(b) Ascomycetes and Basidiomycetes
(d) Oomycetes (c) Deuteromycetes
Answer: (b) Ascomycetes and Basidiomycetes
Explanation: In these groups, two nuclei (n + n) coexist in the same cell without fusion, often forming the dominant stage of the life cycle. - Ergotism in humans is caused by consuming grains infected with:
(b) Ustilago maydis (a) Claviceps purpurea
(d) Alternaria solani (c) Puccinia graminis
Answer: (a) Claviceps purpurea
Explanation: This fungus infects rye and produces toxic alkaloids leading to convulsions, hallucinations, and gangrene — historically known as “St. Anthony’s Fire.” - Homothallism is exhibited by:
(b) Mucor mucedo (a) Rhizopus stolonifer
(d) Agaricus bisporus (c) Neurospora crassa
Answer: (b) Mucor mucedo
Explanation: In homothallic fungi like Mucor, sexual reproduction can occur within a single organism, as it has both mating types. - Which fungus is used in the production of cyclosporin (an immunosuppressant)?
(b) Aspergillus niger (a) Trichoderma polysporum
(d) Candida albicans (c) Penicillium chrysogenum
Answer: (a) Trichoderma polysporum
Explanation: This fungus produces cyclosporin A, crucial in preventing organ transplant rejection by suppressing the immune response. - The reserve food material in fungi is primarily:
(b) Glycogen (a) Starch
(d) Mannitol (c) Laminarin
Answer: (b) Glycogen
Explanation: Fungi store carbohydrates in the form of glycogen, similar to animals, rather than starch which is typical of plants. - Haustoria in fungi are specialized structures for:
(a) Asexual reproduction
(b) Nutrient absorption from hosts
(d) Photosynthesis (c) Spore dispersal
Answer: (b) Nutrient absorption from hosts
Explanation: Haustoria are root-like structures that penetrate host cells to absorb nutrients, typical of parasitic fungi like Puccinia. - The fungus Beauveria bassiana is economically important as a:
(b) Biocontrol agent (a) Source of antibiotics
(d) Producer of citric acid (c) Food source
Answer: (b) Biocontrol agent
Explanation: It infects and kills a wide range of insect pests, making it useful in integrated pest management. - In Aspergillus, parasexuality involves:
(a) Karyogamy followed by meiosis
(b) Formation of heterokaryons
(d) Binary fission (c) Production of ascospores
Answer: (b) Formation of heterokaryons
Explanation: The parasexual cycle begins with heterokaryon formation — hyphae containing genetically distinct nuclei. - Which fungal disease affects silkworms?
(b) Smut (a) Rust
(d) Ergot (c) Muscardine
Answer: (c) Muscardine
Explanation: Caused by Beauveria bassiana, muscardine is a fatal disease of silkworms characterized by a white fungal coating. - The “wine-glass” shaped cells in Candida albicans are called:
(b) Sporangia (a) Conidia
(d) Germ tubes (c) Chlamydospores
Answer: (d) Germ tubes
Explanation: These are filamentous outgrowths that help Candida adhere and invade host tissues, appearing like wine glasses under the microscope. - Which fungus fixes atmospheric nitrogen in symbiosis with plants?
(b) Azotobacter (a) Rhizobium
(d) None of the above (c) Frankia
Answer: (d) None of the above
Explanation: Fungi do not fix atmospheric nitrogen. Nitrogen-fixing symbioses involve bacteria such as Rhizobium or Frankia, not fungi. - Saccharomyces cerevisiae is used in baking due to its ability to produce:
(b) Ethanol and CO₂ (a) Lactic acid
(d) Acetic acid (c) Citric acid
Answer: (b) Ethanol and CO₂
Explanation: During fermentation, Saccharomyces produces CO₂ which causes dough to rise and ethanol which evaporates during baking. - The fungus responsible for “athlete’s foot” is:
(b) Aspergillus (a) Trichophyton
(d) Histoplasma (c) Candida
Answer: (a) Trichophyton
Explanation: Trichophyton species are dermatophytes that infect skin, nails, and hair, causing ringworm and athlete’s foot. - In Agaricus, basidiospores are produced externally on:
(b) Basidium (a) Ascus
(d) Sporangiophore (c) Conidiophore
Answer: (b) Basidium
Explanation: Agaricus (mushroom) is a basidiomycete where sexual spores (basidiospores) are externally produced on club-shaped basidia.
BRYOPHYTES & PTERIDOPHYTES: Structural organization or gametophytes and sporophytes-a brief knowledge. Economic importance.
- In bryophytes, the sporophyte is:
(a) Parasitic on gametophyte
(b) Partially dependent on gametophyte
(c) Independent
(d) Absent
Answer: (b) Partially dependent on gametophyte
Explanation: The sporophyte of bryophytes develops on and depends on the gametophyte for water and nutrients. It carries out limited photosynthesis but is not fully autonomous. - The gametophyte in pteridophytes is called:
(a) Protonema
(b) Prothallus
(c) Thallus
(d) Mycelium
Answer: (b) Prothallus
Explanation: The pteridophyte gametophyte, called prothallus, is a small, free-living, photosynthetic and often heart-shaped structure that bears reproductive organs. - Which bryophyte is used as a surgical dressing?
(a) Funaria
(b) Marchantia
(c) Sphagnum
(d) Anthoceros
Answer: (c) Sphagnum
Explanation: Sphagnum moss has antiseptic properties and excellent water-holding capacity, making it suitable for surgical dressings and wound care in earlier times. - Heterospory is observed in:
(a) Marchantia
(b) Selaginella
(c) Riccia
(d) Funaria
Answer: (b) Selaginella
Explanation: Selaginella, a pteridophyte, produces two types of spores: microspores and megaspores—a condition called heterospory. Most bryophytes are homosporous. - The dominant phase in the life cycle of bryophytes is:
(a) Sporophyte
(b) Gametophyte
(c) Spore
(d) Zygote
Answer: (b) Gametophyte
Explanation: The haploid gametophyte is the main, photosynthetic, and independent stage in bryophytes, unlike in higher plants. - Which pteridophyte is commonly called “horsetail”?
(a) Lycopodium
(b) Selaginella
(c) Equisetum
(d) Psilotum
Answer: (c) Equisetum
Explanation: Equisetum is known as “horsetail” due to its brush-like jointed appearance. It contains silica in its tissues. - Elaters aid in:
(a) Gamete formation
(b) Spore dispersal
(c) Photosynthesis
(d) Water absorption
Answer: (b) Spore dispersal
Explanation: In bryophytes like Marchantia, elaters are hygroscopic structures that help in releasing and dispersing spores by responding to humidity. - Bryophytes lack:
(a) Multicellular gametangia
(b) Embryo stage
(c) Vascular tissues
(d) Chlorophyll
Answer: (c) Vascular tissues
Explanation: Bryophytes are non-vascular plants. They lack specialized conducting tissues like xylem and phloem. - The sporophyte of Funaria consists of:
(a) Foot, seta, and capsule
(b) Rhizoids, stem, and leaves
(c) Protonema and capsule
(d) Seta and foot only
Answer: (a) Foot, seta, and capsule
Explanation: In Funaria (a moss), the sporophyte is composed of a foot (for attachment and absorption), seta (stalk), and capsule (spore-producing structure). - Azolla is used in agriculture for:
(a) Soil erosion control
(b) Biofertilizer
(c) Ornamental purpose
(d) Fodder
Answer: (b) Biofertilizer
Explanation: Azolla forms a symbiotic relationship with the nitrogen-fixing cyanobacterium Anabaena, making it an effective biofertilizer in paddy fields. - Which is NOT a pteridophyte?
(a) Adiantum
(b) Marsilea
(c) Polytrichum
(d) Salvinia
Answer: (c) Polytrichum
Explanation: Polytrichum is a moss (bryophyte), while the others are vascular pteridophytes (ferns). - The first cell of the gametophytic generation in bryophytes is:
(a) Zygote
(b) Spore
(c) Protonema
(d) Antheridium
Answer: (b) Spore
Explanation: The haploid spore germinates to form the gametophyte, starting the gametophytic generation. - In pteridophytes, the stele is:
(a) Always protostele
(b) Protostele or siphonostele
(c) Always eustele
(d) Absent
Answer: (b) Protostele or siphonostele
Explanation: Pteridophytes have different types of steles. Lycopodium has protostele; Pteris and other ferns often have siphonostele. - Water is essential for fertilization in:
(a) Bryophytes only
(b) Pteridophytes only
(c) Both (a) and (b)
(d) Gymnosperms
Answer: (c) Both (a) and (b)
Explanation: Motile sperm in both bryophytes and pteridophytes require a water film to swim to the egg for fertilization. - Rhizophores are found in:
(a) Selaginella
(b) Equisetum
(c) Funaria
(d) Marchantia
Answer: (a) Selaginella
Explanation: Rhizophores are specialized, root-bearing leafless structures that grow downward in Selaginella. - Sphagnum peat is used for:
(a) Fuel
(b) Soil conditioner
(c) Both (a) and (b)
(d) Timber production
Answer: (c) Both (a) and (b)
Explanation: Sphagnum peat is used as fuel and a soil amendment due to its water retention and acidic nature. - The sporophyte of bryophytes is:
(a) Diploid
(b) Haploid
(c) Triploid
(d) Polyploid
Answer: (a) Diploid
Explanation: The sporophyte arises from the fertilized egg (zygote, 2n), making it diploid. - Which pteridophyte is heterosporous?
(a) Lycopodium
(b) Equisetum
(c) Psilotum
(d) Salvinia
Answer: (d) Salvinia
Explanation: Salvinia, an aquatic fern, produces distinct microspores and megaspores—heterospory. - The antheridium in bryophytes produces:
(a) Eggs
(b) Antherozoids
(c) Spores
(d) Protonema
Answer: (b) Antherozoids
Explanation: Antheridia are male reproductive organs that produce motile sperm cells called antherozoids. - Strobili are present in:
(a) Marchantia
(b) Funaria
(c) Equisetum
(d) Riccia
Answer: (c) Equisetum
Explanation: Equisetum produces strobili (cones) at shoot tips, which contain sporangia. - Bryophytes help in:
(a) Soil formation
(b) Water retention
(c) Ecological succession
(d) All of these
Answer: (d) All of these
Explanation: Bryophytes colonize bare rocks, hold water, prevent erosion, and initiate primary succession. - The gametophyte of Selaginella is:
(a) Dioecious
(b) Monoecious
(c) Reduced and endosporic
(d) Independent
Answer: (c) Reduced and endosporic
Explanation: In heterosporous Selaginella, the gametophyte is small and develops inside the spore wall. - In Adiantum, sori are present:
(a) On the ventral surface of leaves
(b) On the dorsal surface of leaves
(c) On the stem
(d) Inside sporocarps
Answer: (b) On the dorsal surface of leaves
Explanation: Sori (clusters of sporangia) are located on the lower surface of Adiantum fronds and are covered by false indusium. - Anthoceros shows symbiotic association with:
(a) Bacteria
(b) Cyanobacteria
(c) Fungi
(d) Viruses
Answer: (b) Cyanobacteria
Explanation: Anthoceros (hornwort) harbors Nostoc in its mucilage cavities for nitrogen fixation. - Which is NOT a pteridophyte characteristic?
(a) Independent sporophyte
(b) Vascular tissues
(c) Seeds
(d) Homospory/heterospory
Answer: (c) Seeds
Explanation: Pteridophytes are vascular and may show homo/heterospory, but they do not produce seeds. - In Marchantia, gemmae cups are involved in:
(a) Sexual reproduction
(b) Vegetative propagation
(c) Spore dispersal
(d) Photosynthesis
Answer: (b) Vegetative propagation
Explanation: Gemmae are asexual, lens-shaped bodies that disperse from gemma cups to form new plants. - The xylem in pteridophytes lacks:
(a) Tracheids
(b) Vessels
(c) Parenchyma
(d) Sclerenchyma
Answer: (b) Vessels
Explanation: Vessels are typically found in angiosperms. Pteridophyte xylem contains only tracheids. - Which pteridophyte is called “resurrection plant”?
(a) Selaginella bryopteris
(b) Equisetum arvense
(c) Lycopodium clavatum
(d) Marsilea
Answer: (a) Selaginella bryopteris
Explanation: This plant revives after complete desiccation and is used in Indian traditional medicine. - The haploid structure in bryophytes is:
(a) Sporophyte
(b) Spore mother cell
(c) Gametophyte
(d) Zygote
Answer: (c) Gametophyte
Explanation: The dominant, photosynthetic, and gamete-producing stage in bryophytes is haploid. - Economic importance of pteridophytes includes:
(a) Ornamental use (e.g., ferns)
(b) Food (e.g., Marsilea)
(c) Medicine (e.g., Lycopodium)
(d) All of these
Answer: (d) All of these
Explanation: Ferns are used as decorative plants, some are edible, and others have medicinal or industrial value.
GYMNOSPERMS & ANGIOSPERMS: Structural organization of ovule, male and female gametophytes in cycas and pixus post-fertilization changes in embryo-sac in angiosperms.
- In Cycas, the male gametophyte is formed within:
(b) Megasporangium (a) Microsporangium
(d) Pollen chamber (c) Ovule
Answer: (a)
Explanation: In Cycas, microspores (pollen grains) develop into male gametophytes inside microsporangia. Pollination transfers them to the pollen chamber of the ovule. - The female gametophyte of Pinus is:
(b) Diploid (a) Haploid
(d) Polyploid (c) Triploid
Answer: (a)
Explanation: The female gametophyte develops from the haploid megaspore and remains haploid until fertilization. - Cycas ovules are:
(b) Anatropous (a) Orthotropous
(d) Circinotropous (c) Hemitropous
Answer: (a)
Explanation: Cycas ovules are orthotropous (straight), with the micropyle, chalaza, and funicle aligned vertically. - The number of archegonia in a Cycas female gametophyte is:
(b) 10–15 (a) 1–5
(d) 3–6 (c) 20–30
Answer: (d)
Explanation: Cycas female gametophyte typically has 3–6 archegonia, each with a large egg cell. - Pollen grains of Pinus have:
(b) Two prothallial cells (a) One prothallial cell
(d) Four prothallial cells (c) No prothallial cells
Answer: (b)
Explanation: Pinus pollen grains contain two degenerated prothallial cells (vegetative cells), a generative cell, and a tube cell. - In Cycas, the pollen tube functions primarily for:
(b) Sperm transfer (a) Nutrient absorption
(d) Photosynthesis (c) Protection
Answer: (a)
Explanation: Unlike angiosperms, the pollen tube in Cycas acts as a haustorium to absorb nutrients; sperm are released for swimming. - The ovule of Pinus is:
(b) Bitegmic (a) Unitegmic
(d) Tritegmic (c) Ategmic
Answer: (a)
Explanation: Pinus ovules have a single integument (unitegmic), unlike angiosperms which are usually bitegmic. - The female gametophyte of Cycas is:
(b) Free-nuclear initially (a) Cellular from the start
(d) Absent (c) Always coenocytic
Answer: (b)
Explanation: The female gametophyte develops through free-nuclear divisions before becoming cellular. - In Pinus, fertilization occurs:
(a) 6 months after pollination
(b) 12 months after pollination
(c) Immediately after pollination
(d) 3 months after pollination
Answer: (b)
Explanation: Pinus has a long interval (12–14 months) between pollination and fertilization. - The nucellus in Cycas is equivalent to:
(b) Megasporangium (a) Female gametophyte
(d) Funicle (c) Integument
Answer: (b)
Explanation: The nucellus is the megasporangium tissue where the megaspore develops. - In Pinus, the number of archegonia present in the female gametophyte is usually:
(d) 10–12 (c) 5–6 (b) 2–3 (a) 1
Answer: (b)
Explanation: The female gametophyte of Pinus typically develops 2 or 3 archegonia near the micropylar end, each containing a large egg cell. - Circinate vernation is a feature of:
(a) Cycas leaflet
(b) Ginkgo leaf
(c) Pinus needle
(d) Gnetum leaf
Answer: (a)
Explanation: In Cycas, young leaflets show circinate vernation, where the leaf is coiled inward at the tip—similar to ferns—providing protection during development. - The embryo in Pinus is formed from:
(a) One zygote only
(b) Free-nuclear stage followed by cellularization
(c) Multiple fertilizations
(d) Fusion of polar nuclei and sperm
Answer: (b)
Explanation: The zygote undergoes a free-nuclear division followed by cell wall formation to develop into an embryo. - Polyembryony in gymnosperms such as Pinus is mainly:
(a) Cleavage polyembryony
(b) Adventive polyembryony
(c) Apomictic polyembryony
(d) False polyembryony
Answer: (a)
Explanation: Cleavage polyembryony occurs when the zygote divides into several embryos; typically, only one survives. - The sperm of Cycas are:
(a) Non-motile
(b) Motile with spiral cilia
(c) Amoeboid
(d) Flagellated with two flagella
Answer: (b)
Explanation: Cycas has large, motile sperms with spiral bands of cilia—a primitive feature in gymnosperms. - The pollen grains of Pinus are dispersed by:
(a) Insects
(b) Birds
(c) Wind
(d) Water
Answer: (c)
Explanation: Pinus is wind-pollinated (anemophilous); its pollen grains have air sacs (wings) for buoyancy and dispersal. - Gnetum differs from other gymnosperms in having:
(a) Vessels in xylem
(b) Flagellated sperm
(c) Archegonia
(d) Resin ducts
Answer: (a)
Explanation: Gnetum possesses vessel elements in its xylem, a feature typical of angiosperms but rare among gymnosperms. - The integument in Cycas ovule leaves a small opening called:
(a) Hilum
(b) Funicle
(c) Micropyle
(d) Chalaza
Answer: (c)
Explanation: The micropyle is the opening through which the pollen tube enters during fertilization. - In Cycas, megaspore develops from:
(a) Archegonium
(b) Nucellus
(c) Megaspore mother cell
(d) Integument
Answer: (c)
Explanation: The megaspore is produced by meiotic division of the diploid megaspore mother cell in the nucellus. - Which of the following genera produces two cotyledons in the embryo stage?
(a) Cycas
(b) Ginkgo
(c) Gnetum
(d) All of the above
Answer: (d)
Explanation: Most gymnosperms like Cycas, Ginkgo, and Gnetum develop two cotyledons in the embryo—hence dicotyledonous. - The function of the nucellus in Cycas ovule is:
(a) Storage of food for embryo
(b) Protection of pollen
(c) Nourishment of megaspore and embryo
(d) Attraction of pollinators
Answer: (c)
Explanation: The nucellus (megasporangium) provides nutrition to the developing gametophyte and embryo. - The leaves of Gnetum resemble dicot leaves in having:
(a) Parallel venation
(b) Pinnate venation and reticulate structure
(c) No stomata
(d) Lack of cuticle
Answer: (b)
Explanation: Gnetum has broad leaves with reticulate venation, similar to dicot angiosperms. - The endosperm in gymnosperms is:
(a) Triploid
(b) Diploid
(c) Haploid
(d) Tetraploid
Answer: (c)
Explanation: Gymnosperm endosperm develops from the haploid female gametophyte before fertilization. - The archegonia of Cycas are formed from:
(a) Megaspore
(b) Integument
(c) Nucellus
(d) Female gametophyte
Answer: (d)
Explanation: The archegonia differentiate from the cells of the haploid female gametophyte inside the ovule. - The ovule in Cycas is surrounded by how many integumentary layers?
(a) One
(b) Two
(c) Three
(d) Four
Answer: (a)
Explanation: Cycas ovule has a single thick integument with three differentiated layers: outer fleshy, middle stony, and inner fleshy. - Gymnosperms differ from angiosperms in:
(a) Absence of ovary
(b) Presence of fruit
(c) Lack of seeds
(d) Absence of pollen
Answer: (a)
Explanation: Gymnosperms have naked ovules not enclosed in an ovary; angiosperms form fruits after fertilization. - In Pinus, the female cone matures in:
(a) 1 year
(b) 2 years
(c) 3 months
(d) 6 months
Answer: (b)
Explanation: Female cones of Pinus take about 2 years to develop from pollination to seed maturation. - The leaves of Pinus are adapted to:
(a) Dry conditions
(b) Aquatic conditions
(c) Tropical rainforests
(d) Saline soils
Answer: (a)
Explanation: Pinus needles are xerophytic, with sunken stomata, thick cuticle, and small surface area to reduce water loss. - Cycas shows resemblance with pteridophytes due to:
(a) Circinate vernation and motile sperm
(b) Presence of flowers
(c) Triploid endosperm
(d) Fruit formation
Answer: (a)
Explanation: Like pteridophytes, Cycas has circinate vernation and motile ciliated sperm—primitive characters not found in other gymnosperms. - Gnetum resembles angiosperms due to the presence of:
(a) Naked seeds
(b) Compound leaves
(c) Vessel elements and absence of archegonia in some species
(d) Circinate vernation
Answer: (c)
Explanation: Gnetum has vessel elements (like angiosperms) and in some species, archegonia are absent, making it unique among gymnosperms. - The stored food material in red algae is:
(a) Starch
(b) Mannitol
(c) Floridean starch
(d) Laminarin
Answer: (c)
Explanation: Red algae (Rhodophyceae) store food as floridean starch, a carbohydrate similar to amylopectin but distinct from true starch. - Which pigment is characteristic of red algae?
(a) Chlorophyll b
(b) Fucoxanthin
(c) Phycocyanin
(d) Phycoerythrin
Answer: (d)
Explanation: Red algae possess phycoerythrin, a red accessory pigment that absorbs blue-green light, allowing them to live in deep waters. - The dominant phase in the life cycle of algae like Spirogyra is:
(a) Gametophyte
(b) Sporophyte
(c) Zygote
(d) Embryo
Answer: (a)
Explanation: Spirogyra exhibits a haplontic life cycle where the dominant phase is the haploid gametophyte. - Red algae mostly reproduce asexually through:
(a) Zoospores
(b) Binary fission
(c) Monospores
(d) Fragmentation
Answer: (c)
Explanation: Red algae typically produce non-motile monospores during asexual reproduction. - The algae commonly used as biofertilizer in paddy fields is:
(a) Spirogyra
(b) Anabaena
(c) Ulothrix
(d) Chlorella
Answer: (b)
Explanation: Anabaena, a nitrogen-fixing cyanobacterium found in symbiotic association with Azolla, is used to enhance fertility in rice paddies. - Alginic acid, a commercially important product, is obtained from:
(a) Red algae
(b) Green algae
(c) Brown algae
(d) Blue-green algae
Answer: (c)
Explanation: Brown algae like Laminaria and Fucus are the source of algin, used in food and textile industries as a thickener. - Motile reproductive structures in green algae typically possess:
(a) Two flagella
(b) Four flagella
(c) Many cilia
(d) No flagella
Answer: (b)
Explanation: In green algae (Chlorophyceae), the motile zoospores usually have four flagella, which are isokont (equal in length). - In red algae, the male gametes are called:
(a) Spermatia
(b) Zoospores
(c) Antherozoids
(d) Isogametes
Answer: (a)
Explanation: Red algae produce non-motile male gametes called spermatia, which rely on water currents for fertilization. - A filamentous green alga with spiral chloroplast is:
(a) Ulothrix
(b) Spirogyra
(c) Volvox
(d) Chlorella
Answer: (b)
Explanation: Spirogyra is named for its prominent spiral chloroplasts and reproduces mainly by fragmentation or conjugation. - The cell wall of brown algae consists of:
(a) Cellulose and agar
(b) Cellulose and pectin
(c) Cellulose and algin
(d) Cellulose only
Answer: (c)
Explanation: Brown algae have a cell wall composed of cellulose and algin, the latter being commercially important. - Agar is obtained from:
(a) Chlorella
(b) Fucus
(c) Gelidium and Gracilaria
(d) Spirogyra
Answer: (c)
Explanation: Agar, used as a culture medium and food additive, is derived from red algae like Gelidium and Gracilaria. - Which of the following is a colonial green alga?
(a) Ulothrix
(b) Chlamydomonas
(c) Volvox
(d) Spirogyra
Answer: (c)
Explanation: Volvox is a motile, colonial green alga where cells form a coordinated colony embedded in a gelatinous matrix. - Algae that show alternation of generations with isomorphic phases are found in:
(a) Ulva
(b) Polysiphonia
(c) Fucus
(d) Chlamydomonas
Answer: (a)
Explanation: In Ulva (sea lettuce), both haploid and diploid phases look alike (isomorphic alternation of generations). - The mucilaginous covering in cyanobacteria helps in:
(a) Photosynthesis
(b) Nitrogen fixation
(c) Protection and floating
(d) Gamete transfer
Answer: (c)
Explanation: The mucilage protects cyanobacteria from desiccation and helps them float near the water surface for light absorption. - A motile unicellular green alga with two flagella is:
(a) Volvox
(b) Chlamydomonas
(c) Ulothrix
(d) Chlorella
Answer: (b)
Explanation: Chlamydomonas is a unicellular, motile green alga with two anterior flagella and cup-shaped chloroplast. - The marine brown algae can grow up to several meters, such as:
(a) Laminaria
(b) Ulothrix
(c) Ectocarpus
(d) Nostoc
Answer: (a)
Explanation: Laminaria, a large brown alga, can grow up to several meters and is commonly found in cold marine waters. - Which group of algae includes both unicellular and multicellular forms?
(a) Rhodophyceae
(b) Chlorophyceae
(c) Phaeophyceae
(d) All of these
Answer: (b)
Explanation: Chlorophyceae (green algae) shows the greatest diversity—from unicellular Chlamydomonas to multicellular Ulva and filamentous Spirogyra. - Carposporophyte stage is found in the life cycle of:
(a) Polysiphonia
(b) Volvox
(c) Chlorella
(d) Ulothrix
Answer: (a)
Explanation: In the triphasic life cycle of red algae like Polysiphonia, the diploid carposporophyte forms after fertilization. - Which of the following is used in space research for oxygen production and food?
(a) Ulva
(b) Spirogyra
(c) Chlorella
(d) Anabaena
Answer: (c)
Explanation: Chlorella, a unicellular green alga, is rich in proteins and used as a food supplement and oxygen producer in space research. - Cyanobacteria differ from true algae by:
(a) Absence of chlorophyll
(b) Presence of nucleus
(c) Prokaryotic cell structure
(d) Presence of mitochondria
Answer: (c)
Explanation: Cyanobacteria (blue-green algae) are prokaryotic organisms lacking membrane-bound organelles and true nucleus, unlike eukaryotic algae. - Which of the following algae has a triphasic life cycle?
(a) Ulothrix
(b) Polysiphonia
(c) Chlamydomonas
(d) Spirogyra
Answer: (b)
Explanation: Polysiphonia, a red alga, exhibits a triphasic life cycle including gametophyte, carposporophyte, and tetrasporophyte generations. - Which pigment is absent in green algae?
(a) Chlorophyll a
(b) Chlorophyll b
(c) Carotenoids
(d) Phycoerythrin
Answer: (d)
Explanation: Phycoerythrin is absent in green algae (Chlorophyceae); it is found in red algae (Rhodophyceae). - The simplest thallus organization is seen in:
(a) Chlorella
(b) Ulothrix
(c) Volvox
(d) Spirogyra
Answer: (a)
Explanation: Chlorella is a unicellular green alga, representing the simplest thallus structure among algae. - Which alga is a good source of β-carotene used in food supplements?
(a) Laminaria
(b) Dunaliella
(c) Chara
(d) Porphyra
Answer: (b)
Explanation: Dunaliella is rich in β-carotene, an antioxidant used in food and cosmetic industries. - Which of the following is known as “stonewort” and resembles higher plants?
(a) Volvox
(b) Chlamydomonas
(c) Chara
(d) Ulva
Answer: (c)
Explanation: Chara, a green alga, is also called “stonewort” due to its calcified body and complexity resembling higher plants. - The specialized cells for nitrogen fixation in cyanobacteria are:
(a) Akinetes
(b) Heterocysts
(c) Hormogonia
(d) Trichomes
Answer: (b)
Explanation: Heterocysts are thick-walled specialized cells in some cyanobacteria where nitrogen fixation occurs under anaerobic conditions. - Cell wall of green algae is mainly composed of:
(a) Cellulose
(b) Pectin
(c) Silica
(d) Lignin
Answer: (a)
Explanation: The cell wall of green algae (Chlorophyceae) is primarily composed of cellulose and sometimes pectin. - Motile spores of algae are called:
(a) Zoospores
(b) Conidia
(c) Aplanospores
(d) Oospores
Answer: (a)
Explanation: Zoospores are motile, flagellated spores produced during asexual reproduction in certain algae like Ulothrix. - Algae mainly differ from fungi in:
(a) Cell wall composition
(b) Absence of chlorophyll
(c) Mode of nutrition
(d) All of the above
Answer: (d)
Explanation: Algae have cellulose cell walls, possess chlorophyll, and are autotrophic, whereas fungi lack chlorophyll, have chitin walls, and are heterotrophic. - Which of the following red algae is used as food in East Asian cuisine?
(a) Ulva
(b) Porphyra
(c) Laminaria
(d) Chara
Answer: (b)
Explanation: Porphyra (nori) is a red alga commonly consumed in Japan, Korea, and China as a food source rich in protein and minerals.
