Diversity Among Plants

Biology, HSSC-KPK First Year. This chapter is split into 23 topics and has 539 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Evolutionary Origin & Diagnostic Features of Plants 24 questions
2. Bryophytes: Characteristics & Moss Life Cycle 26 questions
3. Land Adaptations & Uses of Bryophytes 24 questions
4. Psilopsida, Lycopsida & Sphenopsida 26 questions
5. Ferns: Structure, Leaf Evolution & Life Cycle 26 questions
6. Evolution of Seed & Pollen Tube 22 questions
7. Gymnosperms: Characteristics & Uses 26 questions
8. Angiosperms: Monocots, Dicots & Life Cycle 26 questions
9. Inflorescence Types 24 questions
10. Benefits of Angiosperms & Vascular Plant Success 21 questions
11. Geological Time Chart: Reading Fig 8.1 21 questions
12. Plant Features, Alternation of Generations and Bryophyte Basics 21 questions
13. Moss Life Cycle, Land Adaptations and Peat: Applied 28 questions
14. Tracheophytes and Psilopsida Applied 20 questions
15. Lycopsida, Selaginella and Sphenopsida Applied 20 questions
16. Ferns and Adiantum Applied 20 questions
17. Evolution of Leaf: Microphyllous and Megaphyllous Reasoning 20 questions
18. Seed Evolution and Gymnosperms: Statement Analysis 30 questions
19. Monocots and Dicots: Comparison and Identification 20 questions
20. Angiosperm Flower, Fertilization and Seed Formation Applied 25 questions
21. Inflorescence Types and Angiosperm Benefits Applied 24 questions
22. Chapter 8 Numerical Applications 20 questions
23. Chapter 8 Exercise Questions and Review 25 questions

Sample questions: Diversity Among Plants

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. In plants such as mosses and liverworts, the gametophytic generation is larger, dominant, and autotrophic, while the sporophytic generation is:

• A. Equal in size and complexity to the gametophyte
• B. Smaller, less complex, and heterotrophic, partially or totally dependent on the gametophyte(correct answer)
• C. Entirely absent from the life cycle
• D. Larger and completely independent of the gametophyte

Answer: B.In mosses and liverworts, the gametophytic generation is larger, dominant, and autotrophic (due to chlorophyll), while the sporophytic generation is smaller, less complex, and heterotrophic, being partially or totally dependent on the gametophyte.

Q2. In higher cryptogams such as Lycopodium, Selaginella, ferns, and phanerogams (gymnosperms and angiosperms), the relative development of the two generations is the reverse of that in mosses and liverworts, meaning the sporophyte is:

• A. Completely absent from the life cycle
• B. Smaller and less complex, while the gametophyte dominates
• C. More prominent, structurally complex, and autotrophic, while the gametophyte is smaller and simpler(correct answer)
• D. Identical in size and complexity to the gametophyte

Answer: C.In higher cryptogams and phanerogams, the sporophyte is more prominent, structurally complex, and autotrophic (differentiated into root, stem, and leaves with vascular bundles), while the gametophyte is smaller and simpler — the reverse of the pattern in mosses and liverworts.

Q3. The climax of the expansion of the sporophyte and reduction of the gametophyte is most evident in which plant group, where the gametophytes are tiny, microscopic structures devoid of chlorophyll and totally dependent on the sporophyte?

• A. Angiosperms(correct answer)
• B. Algae such as Ulva
• C. Fungi
• D. Bryophytes

Answer: A.The climax of this evolutionary expansion of the sporophyte (and reduction of the gametophyte) is evident in angiosperms, where the sporophyte is a complex independent plant while the gametophytes are tiny, microscopic, chlorophyll-lacking structures totally dependent on the sporophyte.

Q4. Considering the trend described in the evolution of alternation of generations, which statement best summarizes the overall evolutionary pattern from bryophytes to angiosperms?

• A. There is a progressive increase in the dominance of the gametophyte generation from bryophytes to angiosperms
• B. The sporophyte generation disappears entirely in angiosperms
• C. Both generations remain equally dominant and complex across all plant groups
• D. There is a progressive increase in the dominance and complexity of the sporophyte generation, accompanied by a progressive reduction of the gametophyte generation(correct answer)

Answer: D.From bryophytes (gametophyte-dominant) to angiosperms (sporophyte-dominant, gametophyte reduced to a few cells), there is a clear evolutionary trend of increasing sporophyte dominance and complexity alongside progressive gametophyte reduction.

Q5. Which of the following correctly summarizes the complete life cycle sequence of moss, from spore to spore?

• A. Spore → sporophyte directly → gametophyte → fertilization → spore
• B. Spore → gametophyte → antheridium/archegonium (sperm/egg) → fertilization → zygote → sporophyte → meiosis → spore(correct answer)
• C. Sperm → egg → spore → gametophyte → zygote
• D. Zygote → gametophyte → spore → sporophyte → zygote

Answer: B.The correct life cycle sequence is: spore develops into gametophyte, which produces antheridia/archegonia (sperm/egg), fertilization forms a zygote, which develops into the sporophyte, which produces spores by meiosis, completing the cycle.

Q6. Which set of adaptations listed in the chapter collectively allowed bryophytes to survive the transition from an aquatic to a terrestrial environment?

• A. A chitin cell wall and mycorrhizal association only
• B. A rigid silica shell and flagellated locomotion only
• C. Photosynthesis alone, with no other structural adaptation
• D. A waterproof cuticle, pores for gas exchange, rhizoids for water absorption, heterogamous reproduction, protected reproductive cells, and alternation of generation(correct answer)

Answer: D.The chapter lists multiple coordinated land adaptations in bryophytes: a waterproof cuticle to conserve water, epidermal pores for gas exchange, rhizoids for water absorption, heterogamous sexual reproduction, protection of reproductive cells and embryo, and alternation of generation for genetic diversity.

Q7. According to Fig 8.14 (Life cycle of Adiantum), which is the correct order of stages starting from the mature sporophyte?

From your book: Figure 8.14 (page 181) Full page Open book

• A. Embryo → oospore → fertilization → spores → prothallus
• B. Meiosis → sporophyll → embryo → spores → fertilization
• C. Prothallus → spores → sporangia → sori → sporophyll → embryo
• D. Sporophyll → sori → sporangia → spore mother cells → meiosis → spores → prothallus → antheridia/archegonia → fertilization → oospore → embryo(correct answer)

Answer: D.According to Fig 8.14, the correct sequence from the mature sporophyte is: sporophyll → sori → sporangia → spore mother cells → meiosis → spores → prothallus → antheridia/archegonia (producing antherozoid/egg) → fertilization (syngamy) → oospore → embryo → new sporophyte.

Q8. Which two evolutionary innovations, taken together, are most responsible for freeing seed plants from dependence on external water for reproduction and enabling them to dominate a wide range of terrestrial habitats?

• A. The evolution of chlorophyll and the evolution of cellulose cell walls
• B. The evolution of the seed (with its protective integuments and stored food) and the evolution of the pollen tube(correct answer)
• C. The evolution of cilia and the evolution of the archegonium
• D. The evolution of rhizoids and the evolution of the cuticle

Answer: B.The evolution of the seed (protecting the embryo and megaspore, and storing food) together with the evolution of the pollen tube (delivering sperm to the egg without needing external water) together freed seed plants from dependence on water for reproduction.

Q9. Which of the following correctly describes the complete process of double fertilization and its two products?

• A. One sperm fuses with the egg to form a diploid zygote (developing into the embryo), and the other sperm fuses with the (diploid) endosperm mother cell to form a triploid fusion nucleus (developing into the endosperm)(correct answer)
• B. Both sperms fuse with the egg to form two separate zygotes
• C. Double fertilization produces only a haploid embryo with no endosperm
• D. One sperm fuses with the egg and the other sperm is discarded without any fusion

Answer: A.In double fertilization, one sperm fuses with the haploid egg forming a diploid zygote (which becomes the embryo), while the other sperm fuses with the diploid endosperm mother cell forming a triploid fusion nucleus (which becomes the nutritive endosperm tissue).

Q10. Considering the five medicinal plants discussed in the chapter (Cannabis, Coca, Daffodil, Deadly nightshade, Fever tree), which correctly pairs each plant with its primary medicinal use?

• A. Cannabis-glaucoma/sleeping disorders; Coca-altitude sickness; Daffodil-Alzheimer's; Nightshade-muscle spasms; Fever tree-malaria(correct answer)
• B. Cannabis-malaria; Coca-Alzheimer's; Daffodil-altitude sickness; Nightshade-glaucoma; Fever tree-muscle spasms
• C. All five plants are used exclusively to treat malaria
• D. None of these plants have any documented medicinal use

Answer: A.Each plant has a distinct primary use as described: Cannabis for sleeping disorders/autoimmune diseases/glaucoma, Coca for altitude sickness (via leaf tea) and historically as anaesthetic, Daffodil-derived galantamine for Alzheimer's, Deadly nightshade's atropine for eye muscle relaxation and stopping spasms, and Fever tree's quinine for malaria.