Which plant hormone is widely used as a synthetic herbicide to kill broadleaf weeds in lawns and cereal crops?
A. Kinetin
B. Naphthaleneacetic acid (NAA)
C. 2,4-Dichlorophenoxyacetic acid (2,4-D)
D. Gibberellic acid
Answer: Option C
Solution (By JKExamLibrary)
2,4-D is a synthetic auxin widely used as a selective herbicide. It kills broadleaf dicot weeds without harming monocot crops like wheat, rice, and lawn grasses, as dicots are more sensitive to auxin overdoses, which cause uncontrolled growth and eventual death. NAA and gibberellic acid are used for rooting and growth promotion, and kinetin is a cytokinin.
Explanation:
Transformation is the uptake of free DNA from the surroundings and its incorporation into the bacterial genome. Conjugation requires cell-to-cell contact via pilus, transduction involves bacteriophage, translation is protein synthesis.
Explanation:
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis, spreading through airborne droplets. Cancer, diabetes, and hypertension are non-communicable.
Explanation:
P700 is the reaction center chlorophyll a of photosystem I, absorbing light at 700 nm. It donates electrons to ferredoxin. P680 is the reaction center of PSII. Chlorophyll b and carotenoids are accessory pigments. The two photosystems work in series to transfer electrons from water to NADP⁺.
No comments yet. Be the first to start the discussion!