1.Answer: (c) Heterosporous nature
Explanation: Evolutionary important character of Selaginella is heterosporous nature. Selaginella produces two types of spores microspores and megaspores. Heterospory in the life cycle of Selaginella leads to the formation of seed habit.
2. Answer: (d) Sporopollenin
Explanation: While the exine is composed of sporopollenin, a complex and highly resistant biopolymer containing fatty acids, phenylpropanoids, phenolics, and carotenoids, the intine is largely composed of pectin and cellulose.
3.Answer: (b) Sphagnum
Explanation: Peat is mainly an accumulation of partially decayed vegetation or organic matter and Sphagnum accumulations can store water since both living and dead plants can hold large quantities of water and living matter (like meat eggs) for long-distance transport inside their cells hence, it is responsible for peat formation.
4. Answer: (a) Cellulose
Explanation: The cell wall consists of an inner layer of cellulose and an outer layer of pectin, which is responsible for the slippery texture of the algae. Spirogyra species can reproduce both sexually and asexually. Asexual, or vegetative, reproduction occurs by simple fragmentation of the filaments.
5. Answer: (b) Thick cuticle
Explanation: Conifers (Gymnosperms) are adapted to tolerate extreme environmental conditions because of the thick cuticle, sunken stomata, and needle-like leaves.
6. Answer:(b) Phycoerythrin
Explanation: Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light.
7. Answer: (b) Spirogyra
Explanation:Spirogyra comprise isogamous gametes (similar in size), they are non-flagellated. In Fucus and Volvox, motile male gametes and non-motile female gametes are produced.
8. Answer: (b) Laminaria
Explanation: Brown algae or phaeophyceae are marine algae as they live in seawater. Laminaria is a brown algae and we obtain Iodine from it. Brown algae contains photosynthetic pigments like chlorophyll a, chlorophyll c, carotenoids, and xanthophylls.
9. Answer: (a) Symbiosis
Explanation: Lichens are the symbiotic association linking algae and fungi. The algae benefit their fungal partner by producing organic food compounds through photosynthesis. In return, the fungal partner benefits the algae or cyanobacteria by protecting them and gathering moisture and nutrients from the environment.
10. Answer:: (d) Mosses.
Explanation: The protonema, which grows directly from the germinating spore, is in most mosses an extensive, branched system of multicellular filaments that are rich in chlorophyll. This stage initiates the accumulation of hormones that influence the further growth of newly formed cells.
11. Answer: (b) Gaudikov’s effect
Explanation: Colour of blue-green algae changes according to depth in the sea this is called as Gaudikov's effect. Under normal conditions of growth and almost steady light intensities, their color remains the same, however, as the intensities if the light change or vary they exhibit a drastic change in color.
12. Answer: (c) Generated by introducing foreign DNA in to a cell and regenerating a plant from that cell.
Explanation: Transgenic plants are the ones, whose DNA is modified using genetic engineering techniques. The aim is to introduce a new trait to the plant which does not occur naturally in the species. A transgenic plant contains a gene or genes that have been artificially inserted.
13.Answer: (a) Capsule only
Explanation:The sporophyte of Riccia is the simplest amongst bryophytes. It consists of only a capsule, missing both foot and seta, and does not perform photosynthesis.
14. Answer: (a) the sperms can easily reach up to eggs in the archegonium.
Explanation: Bryophytes are called amphibians of the plant kingdom because they complete their vegetative phase on land but water is necessary for their reproductive phase. Water helps in the maturation and dehiscence of sex organs in bryophytes.
15. Answer: (a) Rhodophyceae
Explanation: Floridean starch is a type of storage glucan found in glaucophytes and in red algae (also known as rhodophytes), in which it is usually the primary sink for fixed carbon from photosynthesis.
16. Answer: (a) brown algae
Explanation: Laminaria (Kelp) and Fucus( Rockweed) are examples of Brown Algae. They both are marine algae. Laminaria is commonly called kelp. This is an example of brown algae it grows in deep coastal waters.
17. Answer: (a) 101
Explanation: One meiotic division produces one matured female gametophyte in an angiosperm. Hence, 101 meiotic divisions are required to produce 101 female gametophytes in an angiosperm.
18. Answer: (a) Sporophytes of ferns live much longer as compared to the sporophytes of mosses.
Explanation: In mosses, sporophytes lack chlorophyll and depend on the photosynthetic gametophyte for food, whereas, in ferns, sporophyte stage has true roots, stem, and leaves and does not depend on the gametophyte. Sporophytes of ferns live much longer as compared to the sporophytes of mosses.
19. Answer: (d) Moss
Explanation: Moss has the largest gametophyte. Mosses are small, soft plants that are typically 1 -10 cm tall, some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations.
20. Answer: (c) zygospore germination
Explanation: In Ulothrix/Spirogyra, meiosis takes place at the time of zygospore germination. It takes place when (+) and (-) plants/filaments result in the formation of the diploid zygote (2x).
21. Answer: (c) surface of ovuliferous scale
Explanation:The tegmen surrounds fleshy endosperm. Inside the endosperm is present in the embryo. At maturity of seed, a thin layer of ovuliferous scale fuses with testa to form a wing (i.e., seeds are winged) which helps in the dispersal of seed.
22. Answer:(a) red algae
Explanation: Agar is a jelly-like material that is derived from Red Algae. The jelly material in algae is due to the presence of unbranched polysaccharides obtained from the cell walls of the red algae.
23. Answer: (d) Green Algae
Explanation: Red rust disease of tea is caused by algae of the genus Cephaleuros. Cephaleuros is a genus of parasitic simple green algae consisting of fourteen species. Its common name is red rust. Hence the disease caused by it is termed as red rust disease.
24. Answer:(a) gymnosperms
Explanation: All cells are haploid. The zygote is developed by the union of one male gamete with the egg and the endosperm is developed by the union of another male gamete with the two polar nuclei. This event is called double fertilization. The correct answer is option (A) Angiosperms.
25. Answer: (c) water
Explanation: In pteridophytes and bryophytes, water is essential for the transport of male gametes. To enter the female gamete, the male gamete requires water through which it can move. In many basic plants, water acts as the channel by which gamete transfer takes place.
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