Title Ex-3 Plant Kingdom (Q-A-Sol).pdf ✅

32 PLANT KINGDOM EXERCISE – 3: Achiever’s Section Systems of Classification 1. Diversification in plant life appeared (a) Due to long periods of evolutionary changes (b) Due to abrupt mutations (c) Suddenly on the Earth (d) By seed dispersal Ans. (a) Sol. Initially, there was no differentiation between the root, stem, and leaves. Plants were thalloid. Vascular tissues were also absent. Plants were evolved by gradual adaptation to habitats. But then diversification in plant life happened due to long periods of evolutionary changes. As these changes last for a longer period, diversification in plants has appeared. Taxonomy: Types 2. Identify the incorrect statement; (a) Numerical taxonomy is based on all observable characteristics. (b) More weightage is given to reproductive characters and all other characters are given equal importance in numerical taxonomy. (c) Cytotaxonomy is based on cytological information like chromosome number, structure, and behaviour. (d) Chemotaxonomy uses the chemical constituents of the plant. Ans. (b) Sol. Numerical taxonomy uses a large number of observable characters to classify organisms. Each character including sexual characters is given equal weightage in this method. Algae (Thallophyta) 3. Read the following statements and find out the incorrect statement. (a) Algae usually reproduce vegetatively by fragmentation, asexually by the formation of different types of spores, and sexually by the formation of gametes. (b) Algae are classified into three classes. (c) Algae are chlorophyll-bearing simple, thalloid, autotrophic, and largely aquatic organisms. (d) The plant body of algae is more differentiated than that of bryophytes. Ans. (d) Sol. Algae are chlorophyll-bearing, simple, thalloid, mostly aquatic (fresh or marine water) organisms that reproduce vegetatively, asexually as well as sexually by the mating of gametes. They are categorised into three classes on the basis of pigments present in them. Their body is less differentiated than bryophytes. Most of them possess a thalloid structure. 4. Read the given statements about algae and select the correct option. i) Plant body is thalloid ii) Largely aquatic iii) Reproduction by vegetative, asexual, and sexual methods iv) Chlamydomonas, Volvox, and Ulothrix are the multicellular algae. (a) Statements (i) and (iii) are true (b) Statements (ii) and (iii) are true (c) Statements (i), (ii) and (iii) are true (d) All statements are true Ans. (c) Sol. -Due to vast diversity in the form and size of the algae, they range from microscopic unicellular to colonial forms and filamentous forms. Chlamydomonas is unicellular. Volvox is unicellular and colonial algae. Ulothrix is a multicellular alga. -Algae are aquatic (marine or freshwater) organisms, but some of the algae occur in moist (terrestrial habitat) such as wet rocks, moist soils, etc. Their plant body is thallus (without any differentiation into roots, stem, and leaves). Their mode of reproduction may be sexual, vegetative, or asexual. 5. Which of the following algae is likely to be found in the deepest waters? (a) Green (b) Brown (c) Red (d) All are found at equal depth Ans. (c) Sol. Red algae are found in the deepest waters. It contains the pigment phycoerythrin. It harvests red coloured light for photosynthesis which is able to penetrate to maximum depth in the water.
PLANT KINGDOM 33 6. Match columns regarding the shape of the chloroplast with their occurrence and select the correct option Type of chloroplast Algae (A) Cup-shaped (1) Ulothrix (B) Girdle shaped (2) Oedogonium (C) Stellate (3) Chlamydomonas (D) Reticulate (4) Zygonema (a) A-2, B-4, C-3, D-1 (b) A-3, B-1, C-4, D-2 (c) A-3, B-4, C-2, D-1 (d) A-2, B-4, C-3, D-1 Ans. (b) Sol. Algae are photosynthetic organisms. The chloroplast present in different algae appears in different shapes. Ulothrix has girdle shaped chloroplast. Oedogonium has a reticulate-shaped chloroplast, Chlamydomonas has a cup-shaped chloroplast and Zygonema have a stellate (star-shaped) chloroplast. 7. Find out the incorrect statement about the Rhodophyceae. (a) Majority are marine with greater concentrations found in the warmer areas. (b) They are also found at great depths of oceans where relatively little light penetrates. (c) They usually reproduce vegetatively by fragmentation. (d) They reproduce asexually by biflagellate zoospores. Ans. (d) Sol. Rhodophyceae is also known as red algae. They are non-flagellated. Asexual reproduction in red algae is carried out by non-motile spores. Bryophytes 8. Bryophytes comprise (a) Dominant phase of gametophyte which produces spores (b) Small sporophyte phase and generally parasitic on the gametophyte (c) The sporophyte is of longer duration (d) Dominant phase of sporophyte which is parasitic. Ans. (b) Sol. Bryophytes comprise a small sporophyte phase which is generally parasitic on the gametophyte. Sporophyte directly grows outside of the fertilized egg and remains dependent on the parent gametophyte for nutrition. 9. Read the following statements regarding bryophytes and select the correct answer. i) Lack of true roots, stems, and leaves. ii) Main plant body is haploid iii) Sex-organs are unicellular and non-jacketed iv) Fertilization produces an embryo inside the water. (a) Statements (i) and (ii) are correct (b) Statements (ii) and (iii) are correct (c) Statements (iii) and (iv) are correct (d) All statements are correct Ans. (a) Sol -The sex organs are multicellular and jacketed. The embryo develops in the venter of archegonium not in water. -Liverworts and mosses together are known as bryophytes. They lack vascular tissues and the plant body is thalloid and haploid. They also lack leaves, stems, or roots but they have stem-like, root-like, and leaf-like structures that perform general functions. 10. Which of the following statements is incorrect? (a) Mosses along with lichens are the first organisms to colonise rocks (b) Sphagnum is used as packing material for transportation of living material. (c) In liverworts, spores are produced after meiosis within the capsule (d) Funaria possesses unicellular unbranched rhizoids. Ans. (d) Sol. -Mosses and lichens are pioneer communities to colonise a xerophytic area or rocks. -Sphagnum has a good water retention capacity and thus is used in packaging living materials like plants during transportation. It keeps the matter moist and prevents it from desiccation. -In liverworts, spores are produced within the capsule and later form a free-living gametophyte. -Rhizoids are hairy structures that can be unicellular or multicellular and help in the attachment of bryophytes to the substratum. In the case of Funaria, the rhizoids are multicellular and branched. 11. Mosses grow in moist and shady places because they (a) Lack roots (b) Lack vascular tissues (c) Require water for the transport of gametes (d) All of the above Ans. (d)
34 PLANT KINGDOM Sol. Mosses grow in moist and shady places because they lack roots and vascular tissues. They require water for the transport of gametes. Mosses lack leaves, stems, or roots but they have cells that perform general functions. They are autotrophic because they contain chloroplast. As they grow in moist and shady places, fertilization takes place only in presence of water. With the help of water antherozoids swim and reach the archegonium. 12. A bryophyte suddenly started reproducing parthenogenetically. The number of chromosomes in the second generation as compared to the parent plant will be (a) Same (b) One half (c) Double (d) Triple Ans. (a) Sol. Parthenogenesis is the type of asexual reproduction involving the development of a female gamete (ovum) into a new organism without fertilization and fusion with a male gamete. The female gamete is haploid. In bryophytes, gametophyte is dominant and haploid. Hence, the number of chromosomes in the second generation as compared to the parent plant will be the same. 13. Archegonia differ from oogonia in having: (a) An egg cell (b) Neck with neck canal cells (c) A jacket layer (d) Both (b) and (c) correct Ans. (d) Sol. Archegonia differ from oogonia in having a neck with neck canal cells and a jacket layer. Oogonium is the female reproductive structure of algae and fungi and they do not have a jacket around the oogonium. In archegonium, embryonic development is seen. The characteristic feature of gametangia is a sterile jacket tissue in the embryophytes in which gamete- producing cells are enclosed and protected along with neck canal cells, egg, and ventral canal cells are present. Pteridophytes 14. Match the columns I and II, and choose the correct combination from the options given Column I Column II a. Selaginella i. Psilopsida b. Equisetum ii. Lycopsida c. Adiantum and Pteris iii. Sphenopsida d. Dryopteris iv Pteropsida (a) a-i, b-ii, c-iii, d-iv (b) a-iii, c-iv, b-i, a-ii (c) a-ii, b-iii, d-ii, c-iv (d) c-iv, a-ii, b-iii, d-iv Ans. (d) Sol. The columns show the classes in pteridophytes and species belonging to it. Selaginella belongs to the class Lycopsida. Equisetum is a species of class Sphenopsida (equisetopsida). Class Pteropsida (also called filicopsida) includes Adiantum, Dryopteris, and Pteris. Psilopsida does not include any of the species given in Column I. Option (d) is the correct answer. 15. Rudimentary seed habit is found in (a) Selaginella (b) Lycopodium (c) Equisetum (d) Adiantum Ans. (a) Sol. Pteridophytes do not show seed habit but some of them show heterospory and retention of female gametophyte carrying embryos which are precursors to seed habit. Selaginella shows rudimentary seed habit but it falls short of seed as there is no permanent retention of female gametophyte or embryo within the megasporangium. Also, there is no integument formation and no indehiscence of megasporangium. 16. The diploid sporophyte is represented by a dominant, independent, photosynthetic, vascular plant body. It alternates with multicellular, autotrophic, independent but short-lived haploid gametophyte. This type of pattern is exhibited by (a) Bryophytes (Sphagnum, Polytrichum) (b) Pteridophytes (Selaginella, Lycopodium) (c) Most of the algal genera (Fucus, Chara, Polysiphonia) (d) Seed plants (gymnosperms and angiosperms) Ans. (b) Sol. Pteridophytes have a haplodiplontic life cycle, with both phases independent of each other. The haploid gametophyte is short-lived and the diploid sporophyte is the dominant phase of their life cycle. 17. A well-developed archegonium with a neck consisting of 4-6 rows of neck canal cells, characterizes (a) Gymnosperms and flowering plants (b) Pteridophytes and gymnosperms (c) Gymnosperms only (d) Bryophytes and pteridophytes
PLANT KINGDOM 35 Ans. (d) Sol. Archegonium is the female sex organ. Archegonium with a long neck containing neck canal cells can be observed in most of the bryophytes. These neck cells are arranged on the venter canal cell. At the time of fertilization neck canal cells (NCC) and venter canal cells (VCC) get disorganized into a mucilaginous mass rich in sucrose and potassium ions. These ions help in attracting the male gametes chemotactically towards the archegonia and help in fertilization. 18. Identify the parts labeled A and B in the given figure of Equisetum and select the correct option. A B (a) Strobilus Rhizome (b) Sporophylls Tuber (c) Sporangia Rhizome (d) Sporophyte Tuber Ans. (a) Sol. The label A shows the strobilus of Equisetum. Strobilus or cones are compact structures made from sporophylls that produce spores by meiosis. Label B shows a rhizome which is an underground structure. Gymnosperms 19. Siphonogamous fertilization takes place in (a) Bryophytes (b) Selaginella (c) Fern (d) Pinus Ans. (d) Sol. In siphonogamous fertilization, a long pollen tube carries two male sperm cells near the egg cell. This is only found in gymnosperms and angiosperms. Pinus is a gymnosperm hence it shows siphonogamous fertilization. 20. The endosperm of gymnosperm develops_____ fertilization whereas the endosperm of an angiosperm develops ______ fertilization. (a) Before, before (b) After, after (c) After, before (d) Before, after Ans. (d) Sol. The endosperm of gymnosperm develops before fertilization whereas the endosperm of an angiosperm develops after fertilization. The endosperm in gymnosperms develops from the haploid megaspore by repeated mitotic divisions. It is formed without fusion of gametes and before the fertilization of megaspore. In angiosperms, the endosperm is triploid as it is formed after double fertilization. It involves the fusion of two polar nuclei and the male gamete. 21. All the following differentiate gymnosperms from the higher cryptogams except (a) Presence of dominant sporophyte (b) Formation of ovules (c) Formation of seeds (d) Type of root system Ans. (a) Sol. -Gymnosperms as well as higher cryptogams (pteridophytes) both show alternation of generation. The sporophyte is the independent and dominant generation in both. -Formation of ovules and seeds are the features of gymnosperms that are absent in pteridophytes. -The taproot system is present in gymnosperms. Pteridophytes have an adventitious root system. 22. Cycas have two cotyledons but are not included in angiosperms because it has (a) No vessels (b) No seeds (c) Naked seeds (d) Flowers Ans. (c)