In Class 11 Final Exams there will be Case studies and Passage Based Questions will be asked, So practice these types of questions. Study Rate is always there to help you. Free PDF Downloads of CBSE Class 11 Biology Chapter 3 Case Study and Passage Based Questions with Answers were Prepared Based on the Latest Exam Pattern. Students can solve Class 11 Biology Case Study Questions Plant Kingdom to know their preparation level.
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In CBSE Class 11 Biology Paper, There will be a few questions based on case studies and passage-based as well. In that, a paragraph will be given, and then the MCQ questions based on it will be asked.
Plant Kingdom Case Study Questions With Answers
Here, we have provided case-based/passage-based questions for Class 11 Biology Chapter 3 Plant Kingdom
Case Study/Passage-Based Questions
Case Study 1: Gymnosperms are plants in which the ovules are not enclosed by any ovary wall and remain exposed, both before and after fertilization. The seeds that develop post-fertilisation, are not covered, i.e., are naked. Gymnosperms include medium-sized trees or tall trees and shrubs. One of the gymnosperms, the giant redwood tree Sequoia is one of the tallest tree species. The roots are generally tap roots. Roots in some genera have a fungal association in the form of mycorrhiza (Pinus), while in some others (Cycas) small specialized roots called coralloid roots are associated with N2–fixing cyanobacteria. The leaves may be simple or compound. In Cycas, the pinnate leaves persist for a few years. The leaves in gymnosperms are well-adapted to withstand extremes of temperature, humidity, and wind. In conifers, the needle-like leaves reduce the surface area. Their thick cuticle and sunken stomata also help to reduce water loss.
The gymnosperms are heterosporous; they produce haploid microspores and megaspores. The two kinds of spores are produced within sporangia that are borne on sporophylls which are arranged spirally along an axis to form lax or compact strobila or cones. The strobili-bearing microsporophylls and microsporangia are called microsporangiate or male strobili. The microspores develop into a male gametophytic generation which is highly reduced and is confined to only a limited number of cells. This reduced gametophyte is called a pollen grain. The development of pollen grains take place within the microsporangia. The cones bearing megasporophylls with ovules or megasporangia are called macrosporangiate or female strobili. The male or female cones or strobili may be borne on the same tree (Pinus). However, in cycas male cones and megasporophylls are borne on different trees. The megaspore mother cell is differentiated from one of the cells of the nucellus. The nucellus is protected by envelopes and the composite structure is called an ovule. The ovules are borne on megasporophylls which may be clustered to form the female cones. The megaspore mother cell divides meiotically to form four megaspores. One of the megaspores enclosed within the megasporangium develops into a multicellular female gametophyte that bears two or more archegonia or female sex organs. The multicellular female gametophyte is also retained within megasporangium.
1.) In gymnosperms, seeds that develop after fertilization are ________________
- a) Covered in ovary walls
- b) Not covered in ovary walls
- c) Covered in ovary sheath
- d) None of the above
Ans: b) Not covered in ovary walls
2.) Identify the correct characteristics of cycus
Characteristic 1 –Leaves pinnate for a few years
Characteristic 2 – Small specialised coralloid roots present
Characteristic 3 – Roots are associated with nitrogen fixing bacteria
Characteristic 4 – Male and female cone are present on different plant
- a) Both 2 and 3
- b) Only 2
- c) 1, 2 and 3
- d) All of the above
Ans: d) All of the above
Which group of fungi is commonly referred to as sac-fungi?
A) Phycomycetes
B) Ascomycetes
C) Basidiomycetes
D) None of the above
Answer: B
In which group of fungi does the mycelium exist as aseptate and coenocytic?
A) Ascomycetes
B) Basidiomycetes
C) Phycomycetes
D) All of the above
Answer: C
Which fungal group includes mushrooms, bracket fungi, or puffballs?
A) Phycomycetes
B) Ascomycetes
C) Basidiomycetes
D) None of the above
Answer: C
What kind of spores are produced exogenously in the special mycelium called conidiophores?
A) Zoospores
B) Ascospores
C) Conidia
D) Basidiospores
Answer: C
Case Study 2:
Bryophytes are mostly terrestrial plants. They are found in moist shady places. But they need water for fertilization and completion of their life cycle. Hence they are called ‘amphibious plants’. The plant body of bryophytes is more differentiated than that of algae. It is thallus-like and prostrate or erect, and attached to the substratum by unicellular or multicellular rhizoids. They lack true roots, stem or leaves. They may possess root-like, leaf-like or stem-like structures. The main plant body of the bryophyte is haploid. It produces gametes, hence is called a gametophyte. The sex organs in bryophytes are multicellular. The male sex organ is called antheridium. They produce biflagellate antherozoids. The female sex organ called archegonium is flask-shaped and produces a single egg. The antherozoids are released into water where they come in contact with archegonium. An antherozoid fuses with the egg to produce the zygote. Zygotes do not undergo reduction division immediately. They produce a multicellular body called a sporophyte. The sporophyte is not free-living but attached to the photosynthetic gametophyte and derives nourishment from it. Some cells of the sporophyte undergo reduction division (meiosis) to produce haploid spores. These spores germinate to produce gametophyte.
They include approximately 960 genera and about 25,000 species. Life cycle of Bryophytes shows sporophytic and gametophytic stages. Vegetative plant body is thalloid or leafy which represents gametophytic generation. Spore producing capsule represents sporophytic generation. Bryophytes have root-like structures called rhizoids. Rhizoids are unicellular in liverworts while multicellular in mosses. Rhizoids absorb water and minerals and also help in fixation of thallus on the substratum. Bryophytes are divided into two groups : liverworts and mosses.
Liverworts (Hepaticeae) – These are lower members of Bryophyta. These are primitive group of Bryophytes. Gametophyte possesses flat plant body called thallus. The thallus is green, dorsiventral, prostrate with unicellular rhizoids. E.g. Riccia, Marchantia
Hornworts (Anthocerotae) – These member possess flattened thallus. The thallus produces horny structures which are called sporophytes hence the name hornworts. e.g. Anthoceros.
Mosses (Musci) – These are advanced members of Bryophyta which possess erect plant body. Gametophytic phase of the life cycle includes two stages namely; protonema stage and leafy stage. The protonema is prostrate green, branched and filamentous (it is also called juvenile gametophyte). It bears many buds. Leafy stage is produced from each bud. Thus protonema helps in the vegetative propagation. The leafy stage has erect, slender stem like (Cauloid) main axis bearing spiral leaf like structures (Phylloid). It is fixed in soil by multicellular branched rhizoids. This stage bears sex organs. Vegetative reproduction takes place by fragmentation and budding in secondary protonema. e.g. Funaria, Polytrichum, Sphagnum, etc
Bryophytes in general are of little economic importance but some mosses provide food for herbaceous mammals, birds and other animals. Species of Sphagnum, a moss, provide peat that have long been used as fuel, and as packing material for trans-shipment of living material because of their capacity to hold water. Mosses along with lichens are the first organisms to colonize rocks and hence, are of great ecological importance. They decompose rocks making the substrate suitable for the growth of higher plants. Since mosses form dense mats on the soil, they reduce the impact of falling rain and prevent soil erosion. The bryophytes are divided into liverworts and mosses.
1.) Lower members of bryophytes are represented by _____________ group of bryophytes
- A) Mosses
- b) Liverworts
- c) Hornworts
- d) Both a and b
Ans: b) Liverworts
2.) In bryophytes, the capsule which produces spore represents ____________
- a) Amphibious generation
- b) Gametophytic generation
- c) Sporophytic generation
- d) None of the above
Ans: c) Sporophytic generation
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