Free Forms and Functions of Plants MCQs with Answers

• A. Abscisic Acid
• B. Auxins
• C. Florigen
• D. Cytokinins

Explanation: Cytokinins delay senescence, maintaining chlorophyll/protein content.

• A. Uptake of minerals
• B. Uptake of water
• C. Elongation of internodes
• D. Ascent of sap

Explanation: Etiolation → rapid internode elongation in darkness.

• A. Phototropism
• B. Photorespiration
• C. Photoperiodism
• D. Geotropism

Explanation: Phytochrome senses day length → regulates flowering.

• A. Thermonasty
• B. Seismonasty
• C. Hydrotropism
• D. Chemonasty

Explanation: Mechanical stimulus → turgor loss in pulvini → leaves fold.

• A. Plasmolysis
• B. Deplasmolysis
• C. Fertilization
• D. Germination

Explanation: Germination = emergence of young plant under favorable conditions.

• A. Meristems
• B. Epistems
• C. Peristems
• D. Mesostems

Explanation: Meristems = actively dividing cells at root/shoot tips or sides.

• A. Primary Growth
• B. Secondary Growth
• C. Tertiary Growth
• D. Both A and B

Explanation: Secondary growth = thickening by vascular & cork cambium.

• A. Xylem
• B. Phloem
• C. Cambium
• D. Cortex

Explanation: Vascular & cork cambium produce secondary tissues → thickening.

• A. Formative Phase
• B. Elongation Phase
• C. Maturation Phase
• D. Differentiation Phase

Explanation: Formative phase in meristems → active cell division.

• A. Acetic Acid
• B. Ethyl Acetic Acid
• C. Methyl Acetic Acid
• D. Indole Acetic Acid

Explanation: Naturally occurring auxin = Indole-3-acetic acid (IAA). Regulates cell elongation, apical dominance, phototropism, root initiation, and…

• A. Seed Dominancy
• B. Shoot Dormancy
• C. Apical Dormancy
• D. Peduncle Dormancy
• E. None of these

Explanation: Apical bud suppresses lateral buds → conserves energy and maintains vertical growth.

• A. Inhibitory Effects
• B. Compensatory Effects
• C. Compression Effects
• D. Comprehensive Effect

Explanation: Removing apical bud allows lateral buds to grow → compensatory effect.

• A. The Formative Phase
• B. Elongation Phase
• C. Maturation Phase
• D. Ovulation Phase

Explanation: Maturation zone → cells complete differentiation into xylem, phloem, and epidermis.

• A. Very High Temperature
• B. High Temperature
• C. Moderate Temperature
• D. Low Temperature
• E. Optimum Temperature

Explanation: Vernalization = induction of flowering after prolonged cold exposure.

• A. Vernalization
• B. Imbibition
• C. Photoperiodism
• D. Apoptosis
• E. Germination

Explanation: Ensures flowering occurs only after cold exposure, preventing premature reproduction.

• A. Facilitated diffusion and osmosis
• B. Diffusion and exocytosis
• C. Pinocytosis and facilitated diffusion
• D. Osmosis and phagocytosis

Explanation: Facilitated diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration with the help…

• A. Stomata
• B. Cuticle
• C. Hydathodes
• D. Lenticles
• E. All of the above

Explanation: Excessive water is removed from the plant body by the process of transpiration.

• A. K
• B. Mg
• C. Cu
• D. Fe

Explanation: Potassium (K+) plays a crucial role in the opening and closing of stomata in plants.

• A. Influx of potassium ions
• B. Efflux of potassium ions
• C. Influx of hydrogen ions
• D. Influx of calcium ions

Explanation: The correct answer is the influx of potassium ions into the guard cells of the stomata.

• A. Evaporation
• B. Transpiration pull
• C. Guttation
• D. Wilting

Explanation: Water evaporates from leaves, creating a suction force that pulls water upward through xylem from roots.