General Science question from JKAS Prelims, 2021 by JKPSC
The growth in response to touch stimulus is called as
Last updated Jun 24, 2026
Correct Answer:
Option C —
Thigmotropism
Understanding Tropisms
A tropism is a biological phenomenon where an organism (usually a plant) grows or turns in a particular direction in response to an external stimulus.
Thigmotropism (Touch): This comes from the Greek word thigma, meaning "touch." It is most commonly seen in climbing plants and vines. When a tendril makes contact with an object like a pole or a fence, it begins to coil around it, allowing the plant to climb upward toward more sunlight.
Why the other options are incorrect:
A) Gravitropism: This is growth in response to gravity. Roots show positive gravitropism (growing down), while stems show negative gravitropism (growing up).
B) Phototropism: This is growth in response to light. Most plant stems will bend toward a light source to maximize photosynthesis. D) Chemotropism: This is growth in response to chemical substances. An example is the growth of a pollen tube toward an ovule during plant fertilization.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
