Online Test — Plant Growth and Development
15 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 15
Growth is best defined as a/an:
Reversible decrease in size
Irreversible increase in size
Change in colour
Loss of weight
Explanation: Growth is an irreversible, permanent increase in size.
Question 2 of 15
Plant growth continues through life because of regions called:
Stomata
Meristems
Lenticels
Stomatal pores
Explanation: Meristems provide indeterminate growth throughout life.
Question 3 of 15
The three phases of growth at the cell level are division, enlargement and:
Maturation
Respiration
Transpiration
Fertilisation
Explanation: The phases are division, enlargement and maturation.
Question 4 of 15
A typical growth curve is:
S-shaped (sigmoid)
A straight line
A circle
Flat
Explanation: Plant growth follows a sigmoid (S-shaped) curve.
Question 5 of 15
The process by which cells become specialised is:
Differentiation
Respiration
Osmosis
Diffusion
Explanation: Differentiation is the specialisation of cells.
Question 6 of 15
The hormone that promotes cell elongation and apical dominance is:
Auxin
Ethylene
Abscisic acid
Cytokinin
Explanation: Auxin promotes elongation and causes apical dominance.
Question 7 of 15
Which hormone helps dwarf plants grow tall and breaks seed dormancy?
Gibberellin
Abscisic acid
Ethylene
Auxin
Explanation: Gibberellins promote stem elongation and germination.
Question 8 of 15
Cytokinins mainly promote:
Cell division and delay ageing
Fruit ripening
Stomatal closure
Seed dormancy
Explanation: Cytokinins promote cell division and delay senescence.
Question 9 of 15
The gaseous plant hormone is:
Auxin
Ethylene
Gibberellin
Cytokinin
Explanation: Ethylene is the gaseous hormone that ripens fruit.
Question 10 of 15
The main growth inhibitor and 'stress hormone' is:
Auxin
Cytokinin
Abscisic acid
Gibberellin
Explanation: Abscisic acid (ABA) is the stress hormone and inhibitor.
Question 11 of 15
Apical dominance means the shoot tip:
Suppresses the growth of side branches
Stops root growth
Causes flowering
Closes stomata
Explanation: Auxin from the tip suppresses lateral buds — apical dominance.
Question 12 of 15
Response of plants to the length of day and night is:
Photoperiodism
Vernalisation
Geotropism
Hydrotropism
Explanation: Photoperiodism is the response to photoperiod.
Question 13 of 15
Plants that flower only when days are shorter than a critical length are:
Long-day plants
Short-day plants
Day-neutral plants
Aquatic plants
Explanation: Short-day plants (e.g. rice) flower with short days.
Question 14 of 15
The plant part that senses day length is the:
Root
Leaf
Flower
Fruit
Explanation: Leaves perceive the photoperiod and signal the shoot tips.
Question 15 of 15
Promotion of flowering by exposure to cold is:
Vernalisation
Photoperiodism
Senescence
Abscission
Explanation: Vernalisation is the cold treatment that promotes flowering.