Choose the correct answer from the four options given below:
Which one of the following does not affect the rate of transpiration?
Topic: Factors affecting transpiration
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(d) Age of the plant.
READ THE WORD "NOT" — you are looking for the one that does NOT affect the rate.
The four EXTERNAL factors affecting transpiration are LIGHT, TEMPERATURE, HUMIDITY and WIND. Three of them appear as options, so the AGE OF THE PLANT is the odd one.
How each of the three works: LIGHT — stomata open in light, so transpiration RISES HUMIDITY — moist air narrows the concentration gradient, so transpiration FALLS (note this works in the opposite direction to the others) WIND — carries the vapour away, so transpiration RISES
In a negative question, identify the group the majority belong to and pick whatever stands outside it.
Age of the plant.