Nutrition in Plants

Free sample questions

Nutrition in Plants — sample Biology questions with answers

1. Question 1

   What is the main role of chlorophyll in photosynthesis?

   • AAbsorb light energy to split water molecules
   • BTransport electrons to the electron transport chain
   • CForm glucose from carbon dioxide
   • DRelease oxygen into the atmosphere

   Answer: A. Absorb light energy to split water molecules

   Chlorophyll absorbs light energy and uses it to split water molecules during photolysis.

2. Question 2

   In the light-dependent reaction, where is water split?

   • AStroma
   • BGranum
   • CThylakoid membrane
   • DIntermembrane space

   Answer: C. Thylakoid membrane

   Water is split at the thylakoid membrane during photolysis, releasing electrons, protons, and oxygen.

3. Question 3

   Which process occurs during the dark phase of photosynthesis?

   • APhotolysis of water
   • BProduction of ATP and NADPH
   • CReduction of carbon dioxide to glucose
   • DActivation of chlorophyll by light

   Answer: C. Reduction of carbon dioxide to glucose

   The dark phase (Calvin cycle) reduces CO${}_2$ to glucose using ATP and NADPH from the light phase.

4. Question 4

   What happens to a plant if the surrounding air has a very low concentration of carbon dioxide?

   • ARate of photosynthesis increases
   • BRate of photosynthesis decreases
   • CStomata open wider
   • DLeaves become greener

   Answer: B. Rate of photosynthesis decreases

   Carbon dioxide is a main substrate; low concentration limits the rate of photosynthesis.

5. Question 5

   Which band on a variegated leaf tested with iodine will produce a blue-black colour?

   • AYellow band (no chlorophyll)
   • BGreen band (has chlorophyll)
   • CWhole leaf
   • DNo band

   Answer: B. Green band (has chlorophyll)

   Only the green band containing chlorophyll can perform photosynthesis and produce starch, which gives a blue-black colour with iodine.