1.Which plant hormone is responsible for cell elongation and growth?
a) Auxin
b) Gibberellin
c) Cytokinin
d) Abscisic Acid
Answer: a) Auxin
2.The process of formation of new roots from the stem or leaf is known as:
a) Apical dominance
b) Phototropism
c) Geotropism
d) Adventitious root formation
Answer: d) Adventitious root formation
3.The apical bud suppresses the growth of lateral buds, a phenomenon known as:
a) Apical dominance
b) Phototropism
c) Geotropism
d) Thigmotropism
Answer: a) Apical dominance
4.In which part of the plant are apical meristems primarily found?
a) Roots
b) Leaves
c) Stems
d) Flowers
Answer: c) Stems
5.The plant hormone responsible for promoting fruit ripening is:
a) Auxin
b) Gibberellin
c) Ethylene
d) Cytokinin
Answer: c) Ethylene
6.Photoperiodism is a response of plants to:
a) Light intensity
b) Duration of light and darkness
c) Temperature
d) Gravity
Answer: b) Duration of light and darkness
7.The opening and closing of stomata are regulated by the movement of:
a) Water
b) Oxygen
c) Potassium ions
d) Carbon dioxide
Answer: c) Potassium ions
8.The growth movement of plant parts in response to touch or mechanical stimulation is known as:
a) Phototropism
b) Geotropism
c) Thigmotropism
d) Hydrotropism
Answer: c) Thigmotropism
9.The process of shedding leaves, flowers, or fruits prematurely is called:
a) Abscission
b) Senescence
c) Dormancy
d) Elongation
Answer: a) Abscission
10.Which of the following plant hormones inhibits the growth of lateral buds?
a) Auxin
b) Gibberellin
c) Cytokinin
d) Abscisic Acid
Answer: c) Cytokinin
11.The hormone responsible for promoting cell division and shoot development is:
a) Auxin
b) Gibberellin
c) Cytokinin
d) Ethylene
Answer: c) Cytokinin
12.The bending of a plant part towards light is known as:
a) Phototropism
b) Geotropism
c) Thigmotropism
d) Hydrotropism
Answer: a) Phototropism
13.The enzyme responsible for breaking down cell walls during abscission is:
a) Amylase
b) Cellulase
c) Protease
d) Lipase
Answer: b) Cellulase
14.The process of seed germination is inhibited by:
a) Gibberellin
b) Abscisic Acid
c) Cytokinin
d) Ethylene
Answer: b) Abscisic Acid
15.The primary site of action of auxins is in the:
a) Roots
b) Leaves
c) Meristems
d) Flowers
Answer: c) Meristems
16.The movement of plant roots towards water is known as:
a) Phototropism
b) Geotropism
c) Hydrotropism
d) Thigmotropism
Answer: c) Hydrotropism
17.A plant with a short-day requirement for flowering will flower when:
a) Days are short and nights are long
b) Days are long and nights are short
c) Day and night duration are equal
d) Temperature is low
Answer: a) Days are short and nights are long
18.The process of shedding of old and mature leaves is known as:
a) Abscission
b) Senescence
c) Dormancy
d) Elongation
Answer: b) Senescence
19.The plant hormone involved in seed dormancy and closing of stomata is:
a) Auxin
b) Gibberellin
c) Abscisic Acid
d) Ethylene
Answer: c) Abscisic Acid
20.The hormone responsible for promoting the elongation of internodes and stem growth is:
a) Auxin
b) Gibberellin
c) Cytokinin
d) Ethylene
Answer: b) Gibberellin