Botany

Part 1 – Plant Cell, Plant Tissues, Plant Anatomy, Plant Morphology, Plant Physiology, Plant Diversity

1. BOTANY – INTRODUCTION

Botany is the branch of biology dealing with the study of plants. It includes the structure, growth, reproduction, metabolism, evolution, classification and economic importance of plants. Botany is essential for agriculture, forestry, medicine, biotechnology and environmental conservation.

Major Branches of Botany:

• Morphology – External structure of plants
• Anatomy – Internal structure
• Cytology – Cell study
• Histology – Tissue study
• Physiology – Plant functions
• Genetics – Heredity
• Taxonomy – Classification
• Ecology – Plant-environment relationship
• Embryology – Development of embryo
• Paleobotany – Fossil plants
• Plant Pathology – Plant diseases
• Economic Botany – Useful plants
• Biotechnology – Modern plant improvement

2. PLANT CELL

Cell is the structural and functional unit of life. Robert Hooke discovered cells in cork (1665). Schleiden proposed that plants are composed of cells.

Cell Theory:

• All living organisms are made of cells.
• Cell is the basic unit of life.
• New cells arise from pre-existing cells (Virchow).

Plant Cell Characteristics: Cell wall present, large central vacuole, chloroplasts present, fixed shape, stores starch, plastids present.

Cell Wall: The cell wall is composed mainly of cellulose.

Functions: Gives rigidity, protects the cell, prevents bursting, allows diffusion of water.

Layers: Primary wall, Secondary wall, Middle lamella (contains calcium pectate).

Plasma Membrane: A selectively permeable membrane made of phospholipids and proteins. Functions: controls entry and exit of substances, cell communication, transport of molecules.

Cytoplasm: Semi-fluid matrix where metabolic reactions occur. Contains organelles, enzymes, cytoskeleton.

Nucleus: Discovered by Robert Brown. Parts: Nuclear membrane, Nucleoplasm, Nucleolus, Chromatin. Functions: controls cell activities, stores DNA, protein synthesis regulation.

Plastids:

• Chloroplast – Contains chlorophyll. Functions: photosynthesis, formation of glucose, oxygen release.
• Chromoplast – Contains carotenoid pigments. Responsible for yellow, orange and red colours.
• Leucoplast – Colourless plastids. Store starch, fats and proteins.

Mitochondria: Powerhouse of the cell. Functions: ATP production, cellular respiration.

Endoplasmic Reticulum: Rough ER – contains ribosomes, protein synthesis. Smooth ER – lipid synthesis, detoxification.

Golgi Apparatus: Called Dictyosomes in plants. Functions: packaging, secretion, cell wall material formation.

Ribosomes: Protein synthesis.

Vacuole: Large in plant cells. Functions: storage, maintains turgidity, waste disposal.

3. CELL DIVISION

Mitosis: Occurs in somatic cells. Stages: Prophase, Metaphase, Anaphase, Telophase. Importance: growth, repair, asexual reproduction.

Meiosis: Occurs in reproductive cells. Produces four haploid cells. Importance: variation, maintains chromosome number.

4. PLANT TISSUES

Tissue is a group of similar cells performing similar functions.

Meristematic Tissue: Actively dividing tissue. Characteristics: small cells, thin walls, dense cytoplasm, large nucleus, no intercellular spaces.

• Apical Meristem – Present at shoot and root tips. Responsible for increase in length.
• Intercalary Meristem – Present at internodes. Responsible for regrowth in grasses.
• Lateral Meristem – Cambium and cork cambium. Responsible for secondary growth.

Permanent Tissue: Derived from meristematic tissue.

Simple Permanent Tissue:

• Parenchyma – Living tissue. Functions: storage, photosynthesis, healing. Special types: Chlorenchyma, Aerenchyma.
• Collenchyma – Living tissue. Functions: mechanical support, flexibility. Found in leaf stalk, young stem.
• Sclerenchyma – Dead tissue. Types: Fibres, Sclereids. Functions: strength, protection.

Complex Permanent Tissue:

• Xylem – Conducts water and minerals. Elements: Tracheids, Vessels, Xylem fibres, Xylem parenchyma.
• Phloem – Conducts food. Elements: Sieve tubes, Companion cells, Phloem fibres, Phloem parenchyma.

5. PLANT ANATOMY

Plant anatomy deals with internal organization.

Root Anatomy: Layers: Epidermis, Cortex, Endodermis, Pericycle, Vascular bundle, Pith. Functions: absorption, anchorage, storage.

Stem Anatomy: Features: Cuticle, Epidermis, Cortex, Vascular bundles, Pith. Functions: support, transport, storage.

Leaf Anatomy: Layers: Upper epidermis, Mesophyll (Palisade tissue, Spongy tissue), Lower epidermis, Stomata. Functions: photosynthesis, transpiration, gas exchange.

6. PLANT MORPHOLOGY

Study of external features.

Root: Functions: absorption, anchorage, food storage. Types: Tap Root (dicots), Fibrous Root (monocots), Adventitious Root (arises from stem or leaves). Modifications: prop roots, pneumatophores, storage roots.

Stem: Functions: support, transport, food storage. Modifications: Rhizome, Tuber, Corm, Bulb, Runner, Stolon, Offset, Sucker.

Leaf: Functions: photosynthesis, transpiration, respiration. Parts: Leaf base, Petiole, Lamina. Venation: Reticulate, Parallel. Arrangement: Alternate, Opposite, Whorled. Leaf Modifications: Spines, Tendrils, Storage leaves, Insectivorous leaves.

Flower: Reproductive organ of angiosperms. Whorls: Calyx, Corolla, Androecium, Gynoecium. Types: Complete, Incomplete, Bisexual, Unisexual, Regular, Irregular. Inflorescence: Racemose, Cymose.

Fruit: Develops from ovary. Types: Simple, Aggregate, Multiple. Functions: protection, seed dispersal.

Seed: Contains: Seed coat, Cotyledons, Embryo. Types: Monocot, Dicot.

7. PHOTOSYNTHESIS

Photosynthesis is the synthesis of food using sunlight.

Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Requirements: Sunlight, Chlorophyll, Carbon dioxide, Water. Occurs in chloroplast.

Light Reaction: Occurs in grana. Produces ATP, NADPH, Oxygen.

Dark Reaction: Occurs in stroma. Produces glucose.

Importance: food production, oxygen release, maintains atmospheric balance.

8. PLANT RESPIRATION

Respiration is oxidation of food to release energy.

Equation: Glucose + Oxygen → Carbon dioxide + Water + ATP

Types:

• Aerobic – Requires oxygen, more ATP.
• Anaerobic – Without oxygen, less ATP.

Stages: Glycolysis, Krebs Cycle, Electron Transport Chain.

9. TRANSPIRATION

Loss of water through aerial parts.

Types: Stomatal, Cuticular, Lenticular.

Importance: cooling, mineral transport, water movement.

Factors Affecting: temperature, humidity, wind, light.

10. MINERAL NUTRITION

Essential Elements:

Macronutrients: Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur.

Micronutrients: Iron, Zinc, Copper, Manganese, Boron, Molybdenum, Chlorine, Nickel.

Deficiency Symptoms:

• Nitrogen – Yellow leaves, poor growth
• Phosphorus – Purple leaves
• Potassium – Leaf scorching
• Iron – Chlorosis

11. PLANT HORMONES

• Auxins – Cell elongation, root formation, apical dominance.
• Gibberellins – Stem elongation, seed germination, flowering.
• Cytokinins – Cell division, delay ageing.
• Ethylene – Fruit ripening, leaf fall.
• Abscisic Acid (ABA) – Dormancy, stomatal closure, stress resistance.

12. PLANT MOVEMENTS

Tropic Movements: Phototropism (response to light), Geotropism (response to gravity), Hydrotropism (response to water), Thigmotropism (response to touch).

Nastic Movements: Independent of stimulus direction. Example: Touch-me-not (Mimosa pudica).

13. PLANT DIVERSITY

Plants are broadly classified into: Algae, Bryophytes, Pteridophytes, Gymnosperms, Angiosperms.

Evolutionary Trend: Algae → Bryophytes → Pteridophytes → Gymnosperms → Angiosperms.

Key TNPSC Points to Remember:

• Cell wall is made mainly of cellulose.
• Dictyosome is the plant Golgi body.
• Xylem transports water and minerals.
• Phloem transports prepared food.
• Chloroplast is the site of photosynthesis.
• Mitochondria are the powerhouse of the cell.
• Auxin promotes cell elongation.
• ABA is the stress hormone.
• Tap root is characteristic of dicots.
• Fibrous root is characteristic of monocots.
• Palisade cells contain maximum chloroplasts.
• Stomata regulate transpiration and gas exchange.
• Mitosis produces two identical cells.
• Meiosis produces four haploid cells.
• Photosynthesis occurs in chloroplasts, while respiration occurs mainly in mitochondria.

Part 2 – Plant Reproduction, Genetics, Molecular Biology, Plant Biotechnology, Ecology, Environmental Botany & Economic Botany

14. PLANT REPRODUCTION

Reproduction is the biological process by which plants produce new individuals. It is of two types: Asexual reproduction and Sexual reproduction.

Asexual Reproduction: Only one parent is involved. No fusion of gametes occurs. Offspring are genetically identical to the parent (clones).

Advantages: Rapid multiplication, maintains desirable characters, no need for pollination or fertilization, useful for commercial propagation.

Methods – Vegetative Propagation: New plants arise from vegetative organs.

Natural Methods:

• Stem – Potato (tuber), Ginger (rhizome), Onion (bulb), Colocasia (corm)
• Root – Sweet potato, Dahlia
• Leaf – Bryophyllum, Begonia

Artificial Methods: Cutting (Rose, Sugarcane), Layering (Jasmine), Grafting (Mango, Citrus), Budding (Rose), Tissue culture (Banana, Orchid).

Sexual Reproduction: Involves fusion of male and female gametes.

Flower Structure: Four floral whorls: Calyx, Corolla, Androecium (male), Gynoecium (female).

Male Reproductive Organ: Stamen consists of Filament and Anther. Anther produces pollen grains.

Female Reproductive Organ: Pistil consists of Stigma, Style, Ovary. Ovules are present inside ovary.

Pollination: Transfer of pollen from anther to stigma.

Self Pollination: Pollen reaches stigma of same flower or same plant. Advantages: maintains purity, less pollen wastage. Disadvantages: less variation, reduced adaptability.

Cross Pollination: Occurs between different plants of same species.

Agents: Wind (Anemophily) – Maize, Rice, Wheat; Water (Hydrophily) – Vallisneria; Insects (Entomophily) – Sunflower, Hibiscus; Birds (Ornithophily); Bats (Chiropterophily).

Advantages: hybrid vigour, greater variation, better adaptability.

Fertilization: Fusion of male and female gametes.

Double Fertilization: Unique feature of angiosperms. One male gamete + Egg → Zygote. Second male gamete + Polar nuclei → Endosperm. Importance: nourishes embryo, characteristic feature of flowering plants.

Seed Formation: After fertilization: Ovary → Fruit; Ovule → Seed; Zygote → Embryo.

15. GENETICS

Genetics is the science of heredity. Father of Genetics: Gregor Johann Mendel.

Mendel's Experiments: Conducted on Garden Pea (Pisum sativum). Reasons for selection: short life cycle, self pollination, easily cross pollinated, many contrasting characters.

Mendel's Laws:

• Law of Dominance – Dominant trait expresses itself. Example: Tall dominates dwarf.
• Law of Segregation – Alleles separate during gamete formation.
• Law of Independent Assortment – Different traits assort independently.

Important Terms: Gene (unit of heredity); Allele (alternative form of gene); Genotype (genetic constitution); Phenotype (external appearance); Homozygous (TT or tt); Heterozygous (Tt); Dominant Gene (expressed in heterozygous condition); Recessive Gene (expressed only in homozygous condition).

Chromosomes: Discovered by Waldeyer. Human chromosome number: 46; Rice: 24; Maize: 20.

DNA: Full form: Deoxyribonucleic Acid. Discovered by Friedrich Miescher. Double helix model: Watson and Crick (1953). Functions: genetic information storage, protein synthesis, heredity.

RNA: Full form: Ribonucleic Acid. Types: mRNA, tRNA, rRNA. Functions: protein synthesis.

16. MOLECULAR BIOLOGY

Central Dogma: DNA → RNA → Protein.

Replication: DNA copies itself before cell division.

Transcription: DNA produces RNA.

Translation: RNA synthesizes proteins.

17. PLANT BIOTECHNOLOGY

Application of biological techniques to improve plants.

Objectives: disease resistance, high yield, drought tolerance, improved nutrition.

Tissue Culture: Growing plant cells on artificial nutrient medium. Principle: Totipotency (ability of a single cell to develop into a complete plant).

Advantages: rapid multiplication, disease-free plants, rare plant conservation, year-round propagation. Applications: Banana, Sugarcane, Potato, Orchid.

Genetic Engineering: Transfer of useful genes into plants. Advantages: pest resistance, herbicide tolerance, improved nutritional quality. Examples: Bt Cotton, Golden Rice.

Biofertilizers: Microorganisms increasing soil fertility. Examples: Rhizobium, Azotobacter, Azospirillum, Blue-green algae. Benefits: nitrogen fixation, reduce chemical fertilizer use, improve soil health.

Biopesticides: Biological agents used to control pests. Examples: Bacillus thuringiensis (Bt), Trichoderma, Neem products.

18. ECOLOGY

Ecology is the study of interactions between organisms and environment. Father of Ecology: Ernst Haeckel.

Ecosystem: Functional unit consisting of living and non-living components.

Components: Abiotic: Water, Air, Soil, Temperature, Light. Biotic: Producers (green plants), Consumers (herbivores, carnivores, omnivores), Decomposers (bacteria, fungi).

Food Chain: Sequence of energy transfer. Example: Grass → Grasshopper → Frog → Snake → Eagle.

Food Web: Network of interconnected food chains. Advantages: stability, alternative food sources.

Ecological Pyramid: Three types: Pyramid of Number, Pyramid of Biomass, Pyramid of Energy (always upright).

Ecological Succession: Gradual replacement of one community by another. Types: Primary succession, Secondary succession.

Biodiversity: Variety of living organisms. Levels: Genetic diversity, Species diversity, Ecosystem diversity. Importance: ecological balance, food security, medicines, agriculture.

Biodiversity Hotspots: Regions with rich endemic species. India contains parts of: Western Ghats, Eastern Himalayas, Indo-Burma, Sundaland (Nicobar Islands).

19. ENVIRONMENTAL BOTANY

Pollution:

• Air Pollution – Causes: industries, vehicles. Effects: acid rain, global warming.
• Water Pollution – Sources: industrial waste, sewage. Effects: eutrophication, aquatic life destruction.
• Soil Pollution – Causes: chemical fertilizers, pesticides.
• Noise Pollution – Causes: traffic, industries.

Greenhouse Effect: Main gases: Carbon dioxide, Methane, Nitrous oxide, Water vapour. Effects: global warming, climate change, sea level rise.

Ozone Layer: Protects Earth from ultraviolet rays. Ozone depletion caused by: CFCs.

Conservation:

• In-situ Conservation – Protection in natural habitat. Examples: National Parks, Wildlife Sanctuaries, Biosphere Reserves.
• Ex-situ Conservation – Outside natural habitat. Examples: Botanical gardens, Seed banks, Gene banks.

20. ECONOMIC BOTANY

Study of economically useful plants.

• Cereals: Rice, Wheat, Maize.
• Pulses: Black gram, Green gram, Red gram, Bengal gram.
• Oil Seeds: Groundnut, Mustard, Sunflower, Sesame, Coconut, Castor.
• Fibre Crops: Cotton, Jute, Flax, Coir.
• Sugar Crops: Sugarcane, Sugar beet.
• Beverage Crops: Tea, Coffee, Cocoa.
• Spices: Pepper, Cardamom, Clove, Turmeric, Ginger, Coriander.
• Medicinal Plants: Neem, Tulsi, Amla, Ashwagandha, Aloe vera, Turmeric.
• Timber Plants: Teak, Sandalwood, Rosewood, Sal, Bamboo.

21. IMPORTANT BOTANISTS

• Theophrastus – Father of Botany
• Linnaeus – Father of Taxonomy
• Gregor Mendel – Father of Genetics
• Robert Hooke – Cell discovery
• Robert Brown – Nucleus
• Watson & Crick – DNA model
• Miescher – DNA discovery
• Ernst Haeckel – Ecology

22. HIGH-YIELD TNPSC FACTS

• Double fertilization occurs only in angiosperms.
• Totipotency is the basis of tissue culture.
• Rhizobium fixes atmospheric nitrogen in legume roots.
• Bt Cotton is insect resistant.
• Golden Rice is enriched with Vitamin A precursor (β-carotene).
• DNA is the hereditary material in most organisms.
• Energy pyramid is always upright.
• Producers occupy the first trophic level.
• Western Ghats is one of India's biodiversity hotspots.
• Botanical gardens are examples of ex-situ conservation.
• National parks are examples of in-situ conservation.
• Chlorophyll is the primary photosynthetic pigment.
• Endosperm develops after double fertilization and nourishes the embryo.
• Tissue culture is widely used for disease-free banana and orchid propagation.
• Theophrastus is known as the Father of Botany, while Linnaeus introduced the modern system of classification.

Part 3 – Taxonomy, Plant Diversity, Plant Pathology, Important Families & 100 Practice Questions with Answers

23. PLANT TAXONOMY

Taxonomy is the science of identification, nomenclature and classification of plants. Father of Taxonomy: Carolus Linnaeus.

Objectives: identification, classification, naming of plants, establishing evolutionary relationships.

Hierarchy of Classification: Kingdom → Division → Class → Order → Family → Genus → Species.

Example: Kingdom – Plantae; Division – Magnoliophyta; Class – Magnoliopsida; Order – Rosales; Family – Rosaceae; Genus – Rosa; Species – Rosa indica.

Binomial Nomenclature: Introduced by Carolus Linnaeus. Rules: Scientific names contain two words; Genus starts with a capital letter; Species starts with a small letter; Scientific names are italicized.

Examples: Mangifera indica, Oryza sativa, Azadirachta indica.

24. PLANT KINGDOM

A. Algae: Simple chlorophyll-bearing aquatic plants. Characteristics: thalloid body, no true root/stem/leaves, photosynthetic, mostly aquatic. Examples: Chlamydomonas, Spirogyra, Ulva, Sargassum. Importance: oxygen production, food, agar extraction, biofertilizer.

B. Bryophytes: Called Amphibians of Plant Kingdom. Characteristics: small plants, no vascular tissue, require water for fertilization. Examples: Riccia, Marchantia, Funaria. Importance: soil formation, prevent soil erosion.

C. Pteridophytes: First vascular land plants. Characteristics: root, stem and leaves present; vascular tissues developed; reproduce by spores. Examples: Lycopodium, Selaginella, Equisetum, Pteris.

D. Gymnosperms: "Naked seed plants." Characteristics: seeds not enclosed by fruits, woody plants, cone bearing. Examples: Cycas, Pinus, Cedrus, Gnetum. Economic importance: timber, paper, resin.

E. Angiosperms: Flowering plants. Characteristics: flowers present, fruits present, double fertilization, seeds enclosed inside fruits.

Monocots: One cotyledon, parallel venation, fibrous roots, floral parts in multiples of three. Examples: Rice, Maize, Lily.

Dicots: Two cotyledons, reticulate venation, tap root, floral parts in multiples of four or five. Examples: Pea, Mango, Sunflower.

25. IMPORTANT PLANT FAMILIES

• Fabaceae (Leguminosae): Tap root, root nodules, papilionaceous flowers. Pulse crops. Examples: Pea, Gram, Groundnut.
• Solanaceae: Examples: Tomato, Brinjal, Potato, Chilli. Vegetables and medicinal plants.
• Poaceae (Gramineae): Grass family. Examples: Rice, Wheat, Maize, Sugarcane, Bamboo. Food crops.
• Malvaceae: Examples: Cotton, Hibiscus, Ladies finger. Fibre crops.
• Euphorbiaceae: Examples: Castor, Rubber, Tapioca. Oil, rubber.
• Rutaceae: Examples: Lemon, Orange.
• Musaceae: Example: Banana.
• Arecaceae: Examples: Coconut, Palmyra.

26. PLANT PATHOLOGY

Study of plant diseases. Father of Plant Pathology: Anton de Bary.

Causes: Fungi, Bacteria, Viruses, Nematodes, Environmental factors.

Important Diseases:

• Late blight of potato – Phytophthora infestans
• Red rot of sugarcane – Colletotrichum falcatum
• Citrus canker – Xanthomonas
• Rust of wheat – Puccinia
• Smut of maize – Ustilago
• Tobacco Mosaic Disease – TMV

Disease Control: Crop rotation, resistant varieties, healthy seeds, biological control, chemical fungicides, sanitation.

27. ECONOMICALLY IMPORTANT PRODUCTS

• Agar – Red algae
• Rubber – Hevea
• Quinine – Cinchona
• Morphine – Opium poppy
• Tea – Camellia
• Coffee – Coffea
• Cotton fibre – Gossypium
• Jute fibre – Corchorus
• Timber – Teak
• Paper pulp – Bamboo

28. IMPORTANT SCIENTIFIC NAMES

• Rice – Oryza sativa
• Wheat – Triticum aestivum
• Maize – Zea mays
• Mango – Mangifera indica
• Neem – Azadirachta indica
• Banana – Musa paradisiaca
• Coconut – Cocos nucifera
• Cotton – Gossypium herbaceum
• Tea – Camellia sinensis
• Coffee – Coffea arabica
• Groundnut – Arachis hypogaea
• Sugarcane – Saccharum officinarum

29. VERY IMPORTANT TNPSC ONE-LINERS

• Linnaeus is the Father of Taxonomy.
• Theophrastus is the Father of Botany.
• Mendel is the Father of Genetics.
• Bryophytes are amphibians of the plant kingdom.
• Gymnosperms bear naked seeds.
• Angiosperms undergo double fertilization.
• Xylem conducts water.
• Phloem conducts food.
• Chloroplast is the site of photosynthesis.
• Mitochondria are the powerhouse of the cell.
• Auxin promotes cell elongation.
• ABA induces dormancy.
• Rhizobium fixes atmospheric nitrogen.
• Tissue culture is based on totipotency.
• Bt Cotton is insect resistant.
• Golden Rice is rich in β-carotene.
• Rice is a monocot.
• Pea is a dicot.
• Potato is a stem tuber.
• Ginger is a rhizome.
• Onion is a bulb.
• Bryophyllum reproduces through leaves.
• Mosses belong to Bryophyta.
• Ferns belong to Pteridophyta.
• Pine belongs to Gymnosperms.
• Mango belongs to Angiosperms.

TNPSC CTS BOTANY – 100 PRACTICE QUESTIONS WITH ANSWERS

• Father of Botany? – Theophrastus
• Father of Taxonomy? – Carolus Linnaeus
• Father of Genetics? – Gregor Mendel
• Cell discovered by? – Robert Hooke
• Nucleus discovered by? – Robert Brown
• Powerhouse of the cell? – Mitochondria
• Site of photosynthesis? – Chloroplast
• Cell wall mainly consists of? – Cellulose
• Plant Golgi body is called? – Dictyosome
• Water-conducting tissue? – Xylem
• Food-conducting tissue? – Phloem
• Functional unit of life? – Cell
• Growth tissue in plants? – Meristem
• Tissue responsible for secondary growth? – Cambium
• Largest plant cell organelle? – Vacuole
• Pigment responsible for photosynthesis? – Chlorophyll
• Stress hormone? – Abscisic acid
• Fruit ripening hormone? – Ethylene
• Cell elongation hormone? – Auxin
• Cell division hormone? – Cytokinin
• Stem elongation hormone? – Gibberellin
• Root nodules contain? – Rhizobium
• Amphibians of plant kingdom? – Bryophytes
• First vascular plants? – Pteridophytes
• Naked seed plants? – Gymnosperms
• Flowering plants? – Angiosperms
• Double fertilization occurs in? – Angiosperms
• One cotyledon plants? – Monocots
• Two cotyledon plants? – Dicots
• Tap root is seen in? – Dicots
• Fibrous root is seen in? – Monocots
• Parallel venation occurs in? – Monocots
• Reticulate venation occurs in? – Dicots
• Study of fungi? – Mycology
• Study of algae? – Phycology
• Study of fossils? – Paleobotany
• Study of heredity? – Genetics
• Study of tissues? – Histology
• Study of cells? – Cytology
• Study of environment? – Ecology
• Study of diseases? – Pathology
• Father of Ecology? – Ernst Haeckel
• Father of Plant Pathology? – Anton de Bary
• DNA model proposed by? – Watson and Crick
• DNA discovered by? – Friedrich Miescher
• Unit of heredity? – Gene
• Alternative form of gene? – Allele
• Visible character? – Phenotype
• Genetic makeup? – Genotype
• Plant tissue culture is based on? – Totipotency
• Rice belongs to? – Poaceae
• Wheat belongs to? – Poaceae
• Maize belongs to? – Poaceae
• Tomato belongs to? – Solanaceae
• Potato belongs to? – Solanaceae
• Cotton belongs to? – Malvaceae
• Groundnut belongs to? – Fabaceae
• Banana belongs to? – Musaceae
• Coconut belongs to? – Arecaceae
• Lemon belongs to? – Rutaceae
• Potato modification? – Stem tuber
• Ginger modification? – Rhizome
• Onion modification? – Bulb
• Bryophyllum reproduces by? – Leaf
• Sugarcane reproduces by? – Stem cutting
• Mango commonly propagated by? – Grafting
• Jasmine propagated by? – Layering
• Rice scientific name? – Oryza sativa
• Wheat scientific name? – Triticum aestivum
• Mango scientific name? – Mangifera indica
• Neem scientific name? – Azadirachta indica
• Banana scientific name? – Musa paradisiaca
• Coconut scientific name? – Cocos nucifera
• Tea scientific name? – Camellia sinensis
• Coffee scientific name? – Coffea arabica
• Cotton scientific name? – Gossypium herbaceum
• Groundnut scientific name? – Arachis hypogaea
• Sugarcane scientific name? – Saccharum officinarum
• Red rot affects? – Sugarcane
• Late blight affects? – Potato
• Citrus canker affects? – Citrus
• Rust disease affects? – Wheat
• Tobacco Mosaic Virus causes? – Tobacco mosaic disease
• Bt Cotton resists? – Insect pests
• Golden Rice contains? – β-carotene
• Nitrogen fixation in legumes by? – Rhizobium
• Largest biodiversity hotspot in South India? – Western Ghats
• In-situ conservation example? – National Park
• Ex-situ conservation example? – Botanical Garden
• Pyramid always upright? – Energy pyramid
• Primary producers? – Green plants
• Main source of atmospheric oxygen? – Photosynthesis
• Universal energy currency? – ATP
• Male reproductive part of flower? – Androecium
• Female reproductive part of flower? – Gynoecium
• Ovary develops into? – Fruit
• Ovule develops into? – Seed
• Embryo develops from? – Zygote
• Site of dark reaction? – Stroma
• Site of light reaction? – Grana