CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which plant hormone class was first identified partly through its effects on cell division in tissue culture?
A. Cytokinins
B. Carotenoids
C. Sterols only
D. Alkanes
Correct Answer: A
Cytokinins were characterized for their ability to promote cytokinesis in plant tissues.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which hormone is commonly involved in leaf and fruit abscission signaling?
A. Ethylene
B. DNA
C. Chlorophyll
D. Starch
Correct Answer: A
Ethylene participates in senescence and abscission processes.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which hormones often act antagonistically in seed dormancy and germination?
A. Abscisic acid and gibberellins
B. Auxin and water
C. Cytokinin and carbon dioxide
D. Ethylene and oxygen
Correct Answer: A
ABA tends to promote dormancy while gibberellins promote germination.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which hormone commonly promotes root initiation in plant cuttings?
A. Ethylene only
B. Gibberellin only
C. Abscisic acid
D. Auxin
Correct Answer: D
Synthetic and natural auxins are used to stimulate adventitious rooting.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
What is apical dominance largely associated with?
A. Ethylene destroying roots
B. Auxin produced near the shoot apex suppressing lateral bud growth
C. Cytokinin eliminating cell division
D. ABA increasing every side branch
Correct Answer: B
Auxin from the shoot tip contributes to suppression of axillary buds.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which hormone is strongly associated with seed dormancy and stomatal closure during water stress?
A. Ethylene
B. Cytokinin
C. Gibberellin
D. Abscisic acid
Correct Answer: D
ABA helps plants respond to drought and promotes dormancy.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which gaseous plant hormone promotes fruit ripening?
A. Auxin
B. Cytokinin
C. Ethylene
D. Gibberellin
Correct Answer: C
Ethylene is a gaseous hormone that coordinates ripening and several stress responses.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which plant hormone promotes stem elongation and seed germination in many plants?
A. Abscisic acid
B. Salicylic acid only
C. Gibberellin
D. Ethylene only
Correct Answer: C
Gibberellins promote growth processes including internode elongation and germination.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which plant hormone promotes cell division and can delay leaf senescence?
A. Ethylene
B. Cytokinin
C. Abscisic acid
D. Auxin only
Correct Answer: B
Cytokinins stimulate cytokinesis and influence shoot growth and senescence.
CSS - PMS - CCE - PCS - General Science
Plant Hormones
Which plant hormone is strongly associated with cell elongation and phototropism?
A. Cytokinin only
B. Ethylene
C. Abscisic acid
D. Auxin
Correct Answer: D
Auxin gradients help regulate differential growth such as bending toward light.