NEET Botany 2 — Questions and Answers
Question 1: Which plant hormone is responsible for apical dominance?
- Gibberellin
- Cytokinin
- Auxin (Correct answer)
- Ethylene
Correct answer: Auxin
Auxin produced at the apical bud suppresses the growth of lateral buds, a phenomenon called apical dominance.
Question 2: The fluid-mosaic model of plasma membrane was proposed by:
- Watson and Crick
- Singer and Nicolson (Correct answer)
- Schleiden and Schwann
- Robert Hooke
Correct answer: Singer and Nicolson
Singer and Nicolson proposed the fluid-mosaic model in 1972, describing the membrane as a fluid phospholipid bilayer with embedded proteins.
Question 3: Kranz anatomy is typically found in plants that perform:
- C3 photosynthesis
- CAM photosynthesis
- C4 photosynthesis (Correct answer)
- Photorespiration
Correct answer: C4 photosynthesis
Kranz anatomy, with bundle sheath cells surrounding mesophyll cells, is characteristic of C4 plants like maize and sugarcane.
Question 4: Which of the following is NOT a characteristic of gymnosperms?
- Seeds are naked
- Presence of archegonia
- Double fertilization (Correct answer)
- Pollen grains have wings in some species
Correct answer: Double fertilization
Double fertilization is a characteristic of angiosperms, not gymnosperms; gymnosperms have simple fertilization.
Question 5: The enzyme RuBisCO catalyzes which step in the Calvin cycle?
- Reduction of 3-PGA
- Regeneration of RuBP
- Carboxylation of RuBP (Correct answer)
- Phosphorylation of G3P
Correct answer: Carboxylation of RuBP
RuBisCO (ribulose bisphosphate carboxylase/oxygenase) catalyzes the fixation of CO2 by adding it to RuBP to form two molecules of 3-PGA.
Question 6: Vernalization refers to:
- Flowering induced by day length
- Flowering promoted by cold temperature treatment (Correct answer)
- Vegetative growth inhibition by light
- Seed germination triggered by red light
Correct answer: Flowering promoted by cold temperature treatment
Vernalization is the process by which prolonged cold temperature exposure promotes or accelerates flowering in certain plants.
Question 7: Which type of placentation is found in Dianthus (carnation)?
- Axile
- Parietal
- Free central (Correct answer)
- Basal
Correct answer: Free central
Free central placentation, where ovules are attached to a central column without septa, is found in Dianthus and other members of Caryophyllaceae.
NEET Botany 2
Which plant hormone is responsible for apical dominance?