Biological termModerate1 mark
2(i)
Name the following:
The tropic movement of plant parts in response to chemicals.
Topic: Chemotropism
Previous-year question practice database
Answer
Exam answer
CHEMOTROPISM.
Explanation
The prefix always names the stimulus: CHEMO- means chemicals, and -TROPISM means a directional growth movement.
The standard example is the growth of the POLLEN TUBE down the style towards the ovule, attracted by chemicals secreted there — which is how fertilisation is achieved in flowering plants.
The family to learn as a set, since any of them may be asked: PHOTOtropism — light GEOtropism — gravity HYDROtropism — water CHEMOtropism — chemicals THIGMOtropism — touch Read the prefix and the answer follows.
More from Chemical Coordination in Plants
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P. Thigmotropism — Touch
Q. Geotropism — Water
R. Chemotropism — Chemicals
S. Phototropism — Gravity
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