Tiêu đề Ex-2 Plant Kingdom (Q-A-Sol ).pdf ✅

26 PLANT KINGDOM EXERCISE – 2: Previous Year Questions 1. Which of the following algae contains mannitol as reserve food material? (NEET 2021) (a) Ectocarpus (b) Gracilaria (c) Volvox (d) Ulothrix Ans. (a) Sol. The algae are divided into three main classes: Chlorophyceae (green algae), Phaeophyceae (brown algae) and Rhodophyceae (red algae). In brown algae, food is stored as mannitol or laminarin. Ectocarpus is a brown alga, consisting of mannitol as reserve food material. Volvox and Ulothrix are green algae that have starch as stored food material. Gracilaria is a red alga in which food is stored as floridean starch. 2. Which of the following algae produce Carrageen? (NEET 2021) (a) Green algae (b) Brown algae (c) Red algae (d) Blue-green algae Ans. (c) Sol. In red algae, the cell wall is made up of cellulose, pectic compounds and mucopolysaccharide (Phycocolloids). The important phycocolloids are agar and carrageenan. Carrageenan is used as a clearing agent in liquors and leather finishing, and as emulsifier in chocolates, ice-creams, tooth paste, paints, etc. 3. Gemmae are present in: (NEET 2021) (a) Mosses (b) Pteridophytes (c) Some Gymnosperms (d) Some Liverworts Ans. (d) Sol. Asexual reproduction in some liverworts take place by the formation of specialised structures called gemmae. Gemmae are green, multicellular, asexual buds, which develop in small receptacles called gemma cups located on the thalli. The gemmae become detached from the parent body and germinate to form new individuals. 4. Genera like Selaginella and Salvinia produce two kinds of spores. Such plants are known as: (NEET 2021) (a) Homosorus (b) Heterosorus (c) Homosporous (d) Heterosporous Ans. (d) Sol. Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores. Such plants are known as heterosporous. In majority the pteridophytes all the spores are of similar kinds; such plants are called homosporous. 5. Which of the following pairs is of unicellular algae? (NEET 2020) (a) Anabaena and Volvox (b) Chlorella and Spirulina (c) Laminaria and Sargassum (d) Gelidium and Gracilaria Ans. (b) Sol. Chlorella and Spirulina are unicellular algae. They are rich in proteins and hence, used as food supplements even by space travelers. 6. Strobili or cones are found in: (NEET 2020) (a) Marchantia (b) Equisetum (c) Salvinia (d) Pteris Ans. (b) Sol. Strobilus is present on many land plant species. The sporophytes bear sporangia that are subtended by leaf-like appendages called sporophylls. In some cases, sporophylls may form distinct compact structures called strobili or cones (Selaginella, Equisetum). 7. From evolutionary point of view, retention of the female gametophyte with developing young embryo
PLANT KINGDOM 27 on the parent sporophyte for some time, is first observed in (NEET 2019) (a) Mosses (b) Pteridophytes (c) Gymnosperms (d) Liverworts Ans. (b) Sol. In pteridophytes, megaspore is retained for some time on female gametophytes, however, permanent retention is required for seed formation. The development of the zygotes into young embryos takes place within the female gametophytes. This event by pteridophytes exhibits precursors to seed habit. 8. Which of the following statements is correct? (NEET 2018) (a) Horsetails are gymnosperms (b) Selaginella is heterosporous, while Salvinia is homosporous (c) Ovules are not enclosed by ovary walls in gymnosperms (d) Stems are usually unbranched in both Cycas and Cedrus Ans. (c) Sol. -Both horsetails and gymnosperms are vascular plants, but horsetails are not gymnosperms. They are vascular plants that are seedless and reproduce with spores. They belong to Pteridophyta. -Both Selaginella and Salvinia are heterosporous where they have two different sized spores that is microspores and megaspores. -Ovules are not enclosed by ovary walls in gymnosperms. -The stem is erect, stout and unbranched in Cycas. In Pinus and Cedrus, the stem is branched. 9. Which one is wrongly matched? (NEET 2018) (a) Gemma cups – Marchantia (b) Biflagellate zoospores – Brown algae (c) Uniflagellate gametes – Polysiphonia (d) Unicellular organism – Chlorella Ans. (c) Sol. Polysiphonia is a genus of red algae which possess non-motile, non-flagellated asexual spores and gametes. 10. An example of colonial alga is (NEET 2017) (a) Chlorella (b) Volvox (c) Ulothrix (d) Spirogyra Ans. (b) Sol. Volvox is a colonial alga. The colonies are formed of approximately 50,000 cells forming a spherical shape. Volvox is a freshwater unicellular green alga with photosynthetic capability. Other three algae (Chlorella, Ulothrix, Spirogyra) are not colonial algae. 11. Life cycle of Ectocarpus and Fucus respectively are (NEET 2017) (a) Haplontic, Diplontic (b) Diplontic, Haplodiplontic (c) Haplodiplontic, Diplontic (d) Haplodiplontic, Haplontic Ans. (c) Sol. In the haplo-diplontic life cycle, both sporophyte and gametophyte are photosynthetic and free living and these two phases alternate with each other. e.g. Ectocarpus. In diplontic life cycle, only gametes are haploid, gametic meiosis occurs, e.g., Dictyota, Fucus, gymnosperms, angiosperms. 12. Zygotic meiosis is characteristic of (NEET 2017) (a) Marchantia (b) Fucus (c) Funaria (d) Chlamydomonas Ans. (d) Sol. Chlamydomonas is a genus of green algae which are found in damp soil, freshwater, seawater, and in snow also. Zygotic meiosis is mainly seen in some lower plants. In zygotic meiosis, meiotic division takes place in zygote and produces haploid individuals. Predominantly, thallophytes show gametophytic generation i.e., haploid individuals are present. So, these organisms have a haplontic life cycle, with multicellular haploid stage which is the dominant phase and single celled diploid stage. 13. Select the correct statement (NEET 2016) (a) Gymnosperms are both homosporous and heterosporous (b) Salvinia, Ginkgo and Pinus all are gymnosperms
28 PLANT KINGDOM (c) Sequoia is one of the tallest trees (d) The leaves of gymnosperms are not well adapted to extremes of climate Ans. (c) Sol. -Sequoia also known as redwood tree is one of the tallest and hardest trees. It is a gymnosperm. -Gymnosperms are heterosporous. -Ginkgo and Pinus are gymnosperms but Salvinia is pteridophyte. -The leaves of gymnosperms are well adapted to resist extreme climates. 14. In bryophytes and pteridophytes, transport of male gametes requires (NEET 2016) (a) Wind (b) Insects (c) Birds (d) Water Ans. (d) Sol. In the life cycle of both bryophytes and pteridophytes, water plays a very important role because both require water for the transport of male gametes. These male gametes are called antheridia (free swimming sperm cells) which are transported via water to the female gametes that are enclosed in the archegonia. Bryophytes are called amphibians of the plant kingdom because of this. The spread of living pteridophytes is limited and restricted to narrow geographical regions as they require water for fertilisation. 15. Conifers are adapted to tolerate extreme environmental conditions because of (NEET 2016) (a) broad hardy leaves (b) superficial stomata (c) thick cuticle (d) presence of vessels Ans. (c) Sol. Conifers are gymnosperms. They possess needle- shaped leaves which are adapted to not accumulate much snow. The leaves in gymnosperms are well- adapted to withstand extreme environmental conditions of temperature, humidity and wind. In conifers, the needle-like leaves reduce the surface area. Their thick cuticle and sunken stomata also help to prevent water loss. 16. Which one of the following statements is wrong? (NEET 2016) (a) Algae increases the level of dissolved oxygen in the immediate environment. (b) Algin is obtained from red algae, and carrageenan from brown algae. (c) Agar-agar is obtained from Gelidium and Gracilaria. (d) Laminaria and Sargassum are used as food. Ans. (b) Sol. -Algae can perform photosynthesis and release oxygen so it can increase the level of dissolved oxygen in the immediate environment. -Algin is obtained from the outer layer of brown algae and carrageenan from red algae. -Agar-agar is a gelling agent used as the solidifying agent in the liquid culture medium, obtained from the cell wall of red algae like Gelidium and Gracilaria. - Laminaria and Sargassum are used as food. 17. Which one is a wrong statement? (AIPMT 2015) (a) Brown algae have chlorophyll a and c, and fucoxanthin (b) Archegonia are found in bryophyta, pteridophyta and gymnosperms (c) Mucor has biflagellate zoospores (d) Haploid endosperm is a typical feature of gymnosperms Ans. (c) Sol. -Brown algae (Phaeophyceae) has a brown colour due to the presence of fucoxanthin and they also contain chlorophyll a and c. -Archegonia are the flask-shaped female reproductive structures found in bryophytes, pteridophytes, and gymnosperms. -Mucor belongs to the kingdom fungi. They have sexual spores which lack flagella. -Gymnosperms have haploid endosperm because they do not have double fertilization. 18. Which one of the following shows isogamy with non- flagellated gametes? (AIPMT 2014) (a) Sargassum (b) Ectocarpus (c) Ulothrix (d) Spirogyra Ans. (d) Sol. Sexual reproduction takes place through fusion of two gametes. Spirogyra shows isogamy with non- flagellated gametes. In Isogamy, the gametes are similar in size. Spirogyra can reproduce sexually as well as asexually.
PLANT KINGDOM 29 19. Which of the following is responsible for peat formation? (AIPMT 2014) (a) Marchantia (b) Riccia (c) Funaria (d) Sphagnum Ans. (d) Sol. Sphagnum, a moss, is responsible for peat formation and it is also known as peat moss. Peat is the accumulation of partially degraded organic matter or decayed vegetation particularly seen in the peatlands. Peat is sometimes also known as turf. 20. An alga which can be employed as food for human being is (AIPMT 2014) (a) Ulothrix (b) Chlorella (c) Spirogyra (d) Polysiphonia Ans. (b) Sol. Chlorella is a single-celled green alga belonging to the Chlorophyceae. They are spherical in shape and also have high protein content. So that it is considered as a source of food. It is mainly found in freshwater bodies and it is used to make nutrition supplements and medicine. It contains several minerals and vitamins. 21. Male gametophyte with the least number of cells is present in (AIPMT 2014) (a) Pteris (b) Funaria (c) Lilium (d) Fucus Ans. (c) Sol. Among Pteris, Funaria, Lilium and Fucus, the male gametophyte with the least number of cells is seen in Lilium. Lilium is an angiosperm with 3-celled male gametophyte. As we proceed to angiosperm from thallophytes, the gametophyte generation reduces and the sporophyte generation becomes dominant. 22. Select the wrong statement. (NEET 2013) (a) Isogametes are similar in structure, function and behaviour (b) Anisogametes differ either in structure, function and behaviour (c) In oomycetes, female gamete is smaller and motile, while male gamete is larger and non-motile (d) Chlamydomonas exhibits both isogamy and anisogamy and Fucus shows oogamy Ans. (c) Sol. In oomycetes, male gamete is smaller and motile and female gamete is larger and non-motile. Fusion between one large, nonmotile (static) female gamete and a smaller, motile male gamete is termed oogamous, e.g., Volvox, Fucus. 23. Read the following statements (IV) and answer the question which follows I. In liverworts, mosses and ferns, gametophytes are free living. II. Gymnosperms and some ferns are heterosporous. III. Sexual reproduction in Fucus and Volvox is oogamous. IV. The sporophyte in liverworts is more elaborate than that in mosses. How many of the above statements are correct? (NEET 2013) (a) One (b) Two (c) Three (d) Four Ans. (c) Sol. -Liverworts, mosses and ferns have independent free living gametophytes, that is they are free living. -Gymnosperms and some ferns possess different types of spores, they are called heterosporous. -Oogamous means male gamete is small and flagellated while female gamete is non-flagellated and large. Sexual reproduction in Fucus and Volvox is oogamous. -The sporophyte of liverworts is not more elaborate than the mosses. Mosses show a more elaborate sporophyte. So, except for statement IV, the other 3 statements are correct. 24. Cycas and Adiantum resemble each other in having (NEET 2013) (a) Seeds (b) Motile sperms (c) Cambium (d) Vessels Ans. (b) Sol. -Cycas which is a gymnosperm and Adiantum (maidenhair fern) which is a pteridophyte, both have motile sperms as a common feature. -Vessels are absent in both groups, whereas seeds and cambium are present in gymnosperms but not in pteridophytes. 25. Which one of the following is a correct statement? (NEET 2013) (a) Pteridophyte gametophyte has a protonemal and leafy stage. (b) In gymnosperms, female gametophyte is free living.