I. Choose the Best Answer (MCQs)
Q1. Solanum trilobatum is the binomial name of Thoothuvalai. Here the word 'Solanum' refers to ______
- (a) Species (b) Genus (c) Class (d) Orders
Q2. ______ is an example for colonial form of algae.
- (a) Oscillatoria (b) Nostoc (c) Volvox (d) Chlorella
Q3. Floridean starch is a reserve food material of ______
- (a) Chlorophyceae (b) Phaeophyceae (c) Rhodophyceae (d) Cyanophyceae
Q4. The edible mushroom is ______
- (a) Polyporus (b) Agaricus (c) Penicillium (d) Aspergillus
Q5. Soil erosion is prevented by ______ plants.
- (a) Algae (b) Fungi (c) Bryophytes (d) Pteridophytes
Q6. The first vascular cryptogams in land plants are ______
- (a) Bryophytes (b) Pteridophytes (c) Gymnosperms (d) Angiosperms
Q7. The well-developed sporophytic plant body is seen in ______
- (a) Bryophytes (b) Pteridophytes (c) Gymnosperms (d) Angiosperms
Q8. Binomial Nomenclature was first introduced in the year ______
- (a) 1970 (b) 1975 (c) 1978 (d) 1623
Additional MCQs
Q9. Penicillin is an antibiotic, which is extracted from ______
- (a) Algae (b) Fungi (c) Bryophytes (d) Pteridophytes
Q10. ______ is a blue-green algae.
- (a) Chlamydomonas (b) Volvox (c) Oscillatoria (d) Polysiphonia
Q11. ______ is used in space travel as a food source.
- (a) Volvox (b) Chlorella (c) Nostoc (d) Spirogyra
Q12. ______ is an edible alga.
- (a) Polysiphonia (b) Spirulina (c) Nostoc (d) Oscillatoria
Q13. Coralloid roots are seen in ______
- (a) Pinus (b) Cycas (c) Ginkgo (d) Selaginella
Q14. Horse tail refers to ______
- (a) Lycopodium (b) Selaginella (c) Equisetum (d) Pteris
Q15. ______ is a hallucinogenic fungus.
- (a) Agaricus (b) Penicillium (c) Claviceps (d) Aspergillus
Q16. Classification of algae was given by ______
- (a) Linnaeus (b) Fritsch (c) Bentham (d) Hooker
II. Fill in the Blanks
1. The word 'Taxonomy' is derived from Greek. 2. Binomial Nomenclature was first introduced by Gaspard Bauhin. 3. The book "Genera Plantarum" was written by Bentham and Hooker. 4. Monocotyledon seeds bear only one cotyledon. 5. Brown algae belongs to Phaeophyceae class. 6. Agar-Agar is obtained from red algae. 7. The reserve food material of fungi are glycogen and oil. 8. The first true land plant is Pteridophyte. 9. Xylem and phloem are absent in Bryophyte plants. 10. Reticulate venation is present in dicot plants. 11. Minute algae floating on the surface of water are called phytoplanktons. 12. Lichens are an example of symbiosis between algae and fungi. 13. The book written by Linnaeus is titled Species Plantarum. 14. The largest herbarium of India is in Kolkata. 15. The root-like structure in bryophytes is called rhizoid.
III. True or False
Additional True or False
IV. Match the Following
Match 1: Algae Classes
| Column A | Column B | Answer |
|---|---|---|
| 1. Cyanophyceae | (a) Brown algae | 1 — (d) Blue-green algae |
| 2. Chlorophyceae | (b) Red algae | 2 — (c) Green algae |
| 3. Phaeophyceae | (c) Green algae | 3 — (a) Brown algae |
| 4. Rhodophyceae | (d) Blue-green algae | 4 — (b) Red algae |
Match 2: Plant Groups and Features
| Column A | Column B | Answer |
|---|---|---|
| i. Algae | (a) Naked seeds | i — (d) Thallus body |
| ii. Bryophytes | (b) Seeds inside fruit | ii — (e) Amphibians of plant kingdom |
| iii. Pteridophytes | (c) Vascular cryptogams | iii — (c) Vascular cryptogams |
| iv. Gymnosperms | (d) Thallus body | iv — (a) Naked seeds |
| v. Angiosperms | (e) Amphibians of plant kingdom | v — (b) Seeds inside fruit |
Match 3: Examples and Plant Groups
| Column A | Column B | Answer |
|---|---|---|
| i. Funaria | (a) Pteridophyte | i — (d) Bryophyte |
| ii. Nostoc | (b) Algae | ii — (b) Algae |
| iii. Selaginella | (c) Angiosperm | iii — (a) Pteridophyte |
| iv. Mangifera | (d) Bryophyte | iv — (c) Angiosperm |
V. Short Answer Questions
Q1. Define Thallus. Answer: A thallus is a simple plant body that is not differentiated into root, stem, and leaves. It is found in algae and some fungi. Example: The body of Spirogyra or Chlamydomonas.
Q2. What is Binomial Nomenclature? Give an example. Answer: Binomial nomenclature is the system of naming organisms with two words — the first word denotes the genus (capitalised) and the second denotes the species (lowercase). The entire name is italicised or underlined.
Example: Mangifera indica (Mango) — Mangifera = genus, indica = species.
It was first introduced by Gaspard Bauhin in 1623 and later popularised by Carl Linnaeus.
Q3. Write any two characters of dicotyledons. Answer: 1. Seeds have two cotyledons. 2. Leaves show reticulate venation. 3. Root system is tap root system. 4. Flowers are tetramerous or pentamerous (floral parts in 4s or 5s).
Q4. Seeds of gymnosperm plants are naked. Why? Answer: In gymnosperms, the ovules are borne directly on megasporophylls and are not enclosed inside an ovary. Since gymnosperms do not produce flowers or fruits, the seeds remain exposed or naked. That is why they are called "gymnosperms" (gymno = naked, sperma = seed).
Q5. Write any two economic importance of fungi. Answer: 1. Antibiotics: Penicillin is obtained from Penicillium notatum. Other antibiotics like neomycin and erythromycin are also produced by fungi. 2. Food: Mushrooms (Agaricus) are rich in protein and minerals and are widely consumed as food.
Other uses include:
- Fermentation: Yeast (Saccharomyces) is used in baking and brewing.
- Cheese ripening: Species of Penicillium are used to ripen cheese.
Q6. Write the classification of algae. Answer: Algae are classified into the following classes based on their pigments:
| Class | Common Name | Pigment | Example |
|---|---|---|---|
| Cyanophyceae | Blue-green algae | Phycocyanin (blue) | Nostoc, Oscillatoria |
| Chlorophyceae | Green algae | Chlorophyll a and b | Chlamydomonas, Volvox |
| Phaeophyceae | Brown algae | Fucoxanthin (brown) | Fucus, Sargassum |
| Rhodophyceae | Red algae | Phycoerythrin (red) | Polysiphonia, Gelidium |
Q7. What are cryptogams and phanerogams? Answer:
- Cryptogams are plants that reproduce by spores and do not produce visible seeds. They include Algae, Bryophytes, and Pteridophytes. (Crypto = hidden, gamos = marriage)
- Phanerogams are plants that produce visible seeds. They include Gymnosperms and Angiosperms. (Phaneros = visible, gamos = marriage)
VI. Detailed Answer Questions
Q1. Explain the classification of Plant Kingdom. Answer:
The Plant Kingdom is classified into five major groups based on increasing complexity of the plant body:
Q2. Write the differences between the following pairs: Answer:
(a) Monocotyledons and Dicotyledons
| Feature | Monocotyledons | Dicotyledons |
|---|---|---|
| Cotyledons | One cotyledon | Two cotyledons |
| Leaf venation | Parallel venation | Reticulate venation |
| Root system | Fibrous root system | Tap root system |
| Flower parts | Trimerous (in 3s) | Tetramerous or pentamerous (in 4s or 5s) |
| Vascular bundles | Scattered in stem | Arranged in a ring in stem |
| Secondary growth | Absent | Present |
| Examples | Paddy, wheat, grass, banana | Mango, bean, pea, hibiscus |
(b) Gymnosperms and Angiosperms
| Feature | Gymnosperms | Angiosperms |
|---|---|---|
| Seeds | Naked (not enclosed in fruit) | Enclosed inside a fruit |
| Flowers | Absent; produce cones (strobili) | Present; produce flowers |
| Pollination | Only by wind | By wind, water, insects, animals |
| Vascular tissue | Xylem lacks vessels; phloem lacks companion cells | Xylem has vessels; phloem has companion cells |
| Fruit formation | No fruit | Fruit develops from ovary |
| Cotyledons | Usually two or many | One (monocots) or two (dicots) |
| Examples | Pinus, Cycas, Ginkgo | Mango, wheat, rose, bean |
(c) Algae and Fungi
| Feature | Algae | Fungi |
|---|---|---|
| Nutrition | Autotrophic (photosynthetic) | Heterotrophic (saprophytic/parasitic) |
| Pigments | Present (chlorophyll, fucoxanthin, etc.) | Absent |
| Reserve food | Starch | Glycogen and oil |
| Cell wall | Cellulose (in most) | Chitin |
| Habitat | Mostly aquatic | Mostly terrestrial |
| Cell nature | Some prokaryotic, some eukaryotic | All eukaryotic |
| Examples | Spirogyra, Volvox, Sargassum | Agaricus, Penicillium, Yeast |
Q3. Describe Bryophytes in detail. Answer:
Bryophytes are simple, non-vascular land plants that require water for sexual reproduction. They are called the "amphibians of the plant kingdom" because they live on land but need water for the movement of male gametes.
General Characters: 1. Plant body is gametophyte (haploid), which is the dominant phase. 2. No true roots — root-like structures called rhizoids are present for anchorage. 3. Vascular tissues absent — no xylem or phloem. 4. Plant body may be thalloid (in liverworts) or differentiated into stem-like and leaf-like structures (in mosses). 5. Male sex organ: Antheridium (produces motile, biciliate antherozoids). 6. Female sex organ: Archegonium (flask-shaped, contains a single egg). 7. Fertilisation requires water for the antherozoids to swim to the archegonium. 8. Sporophyte is dependent on the gametophyte for nutrition and is short-lived. 9. Vegetative reproduction occurs by fragmentation, gemmae, and tubers.
Classification of Bryophytes (3 classes):
| Class | Common Name | Example | Features |
|---|---|---|---|
| Hepaticae | Liverworts | Riccia, Marchantia | Thalloid body; dorsiventral; no midrib |
| Anthocerotae | Hornworts | Anthoceros | Thalloid body; sporophyte is horn-like |
| Musci | Mosses | Funaria, Sphagnum | Differentiated into stem and leaves; most advanced bryophytes |
Economic Importance:
- Prevent soil erosion: Dense growth holds soil together with rhizoids.
- Peat formation: Sphagnum (peat moss) forms peat, used as fuel and in horticulture.
- Nursery use: Sphagnum moss is used in nurseries to retain moisture around plant roots.
- Nitrogen fixation: Some bryophytes harbour nitrogen-fixing cyanobacteria in their tissues.
- Medicinal: Marchantia has been used in traditional medicine for liver ailments.
Q4. Write about the economic importance of plant groups. Answer:
Economic Importance of Algae: 1. Agriculture: Blue-green algae like Nostoc and Anabaena fix atmospheric nitrogen, increasing soil fertility. 2. Food: Spirulina and Porphyra are used as food. Spirulina is rich in protein (single-cell protein). 3. Agar-Agar: Extracted from red algae (Gelidium, Gracillaria), used in preparing culture media in laboratories and in the food industry. 4. Iodine: Obtained from brown algae like Laminaria (kelp). 5. Space food: Chlorella is rich in proteins and used as a food supplement in space travel. 6. Algin: Extracted from brown algae, used in ice cream and cosmetics.
Economic Importance of Fungi: 1. Antibiotics: Penicillin from Penicillium notatum; used to treat bacterial infections. 2. Food: Mushroom (Agaricus) is a protein-rich edible food. 3. Fermentation: Yeast (Saccharomyces) is used in baking and brewing. 4. Cheese ripening: Penicillium roqueforti and P. camemberti are used in cheese making. 5. Organic acids: Aspergillus niger produces citric acid.
Economic Importance of Pteridophytes: 1. Ornamental: Ferns are grown as ornamental plants in gardens. 2. Medicine: Lycopodium spores are used in medicine. 3. Soil formation: Pteridophytes help in soil formation and conservation.
Economic Importance of Gymnosperms: 1. Paper industry: Wood of Pinus and Agathis is used in paper manufacturing. 2. Soft wood: Conifers like Cedrus and Agathis provide soft wood for construction. 3. Turpentine oil: Extracted from Pinus resin, used in paints and medicine. 4. Edible seeds: Seeds of Pinus gerardiana (chilgoza) are edible. 5. Medicine: Ephedrine (alkaloid) extracted from Ephedra treats asthma and respiratory problems. 6. Ornamental: Araucaria is grown as an ornamental plant.
Medicinal Plants of Tamil Nadu:
| Plant | Tamil Name | Uses |
|---|---|---|
| Acalypha indica | Kuppaimeni | Leaf paste cures skin burns; juice with lemon cures ringworm |
| Aegle marmelos | Vilvam | Unripe fruit treats indigestion; cures chronic diarrhoea |
| Solanum trilobatum | Thoodhuvalai | Leaves and fruits cure cough, cold; used for TB and bronchial asthma |
| Phyllanthus amarus | Keezhanelli | Entire plant treats jaundice; strengthens liver |
| Aloe vera | Sothu Katrazhai | Leaves cure piles, skin inflammation; cures peptic ulcer |
Common Mistakes
- Calling all bryophytes hydrophytes: Bryophytes are amphibians of the plant kingdom — they grow on land but need water for reproduction. They are not true water plants (hydrophytes).
- Confusing the dominant phase in bryophytes and pteridophytes: In bryophytes, the gametophyte is dominant; in pteridophytes, the sporophyte is dominant. Students often mix these up.
- Saying gymnosperms have flowers: Gymnosperms produce cones (strobili), not flowers. Only angiosperms produce flowers.
- Confusing algae classes and pigments: Cyanophyceae (blue-green, phycocyanin), Chlorophyceae (green, chlorophyll), Phaeophyceae (brown, fucoxanthin), Rhodophyceae (red, phycoerythrin). Do not mix up which pigment belongs to which class.
- Stating that binomial nomenclature was introduced by Linnaeus: It was first introduced by Gaspard Bauhin in 1623. Linnaeus later popularised and refined it.
- Confusing thallus with true plant body: A thallus has no differentiation into root, stem, and leaves. Only higher plants (pteridophytes onwards) have true roots, stems, and leaves.
- Writing "Pinus is a closed-seeded plant": Pinus is a gymnosperm with naked seeds. Only angiosperms have seeds enclosed in a fruit.
- Mixing up reserve food materials: Algae store starch; fungi store glycogen and oil. Do not confuse these.
- Confusing coralloid roots with normal roots: Coralloid roots are a special feature of Cycas that harbour nitrogen-fixing cyanobacteria.
Exam Checklist
- [ ] Can you list the five major groups of the Plant Kingdom in order of complexity?
- [ ] Can you define binomial nomenclature and give an example?
- [ ] Can you explain why bryophytes are called "amphibians of the plant kingdom"?
- [ ] Can you distinguish between monocotyledons and dicotyledons (at least 5 differences)?
- [ ] Can you explain why gymnosperms are called "naked-seeded plants"?
- [ ] Can you list the four classes of algae with their pigments and examples?
- [ ] Can you differentiate between the gametophyte and sporophyte phases in bryophytes and pteridophytes?
- [ ] Can you describe the three classes of bryophytes with examples?
- [ ] Can you write the economic importance of algae (at least 4 points)?
- [ ] Can you write the economic importance of gymnosperms (at least 4 points)?
- [ ] Can you differentiate between gymnosperms and angiosperms?
- [ ] Can you name the five medicinal plants of Tamil Nadu with their Tamil names and uses?