Biology

Photosynthesis in Plants

1,492 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice

Match the following: Medium of growth of plants|Function| |a. Water|1. It helps in releasing metabolic energy essential for growth activities.| |b. Oxygen|2. It is required by plants for the synthesis of protoplasm and it acts as a source of energy.| |c. Nutrient|3. It provides the medium for enzymatic activities that is needed for growth.|

  1. a - 3, b - 1, c - 2

  2. a - 2, b - 1, c - 3

  3. a - 1, b - 3, c - 2

  4. a - 1, b - 2, c - 3

  5. a - 3, b - 2, c - 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. Water provides the medium for enzymatic activities that is needed for growth. Oxygen helps in releasing metabolic energy essential for growth activities. Nutrient is required by plants for the synthesis of protoplasm and it acts as a source of energy.

Multiple choice

Why do leaves look green in colour?

  1. Due to presence of carbon dioxide

  2. Due to chlorofluorocarbons

  3. Due to chlorophyll

  4. Due to plants planted in soil

  5. Due to sunlight
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chlorophyll is the main agent responsible for green leaves.

Multiple choice

Respiration in plants

  1. results in the formation of vitamins

  2. is characteristic of all living cells

  3. often requires carbon dioxide

  4. occurs only during day
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cellular respiration occurs in all living cells (plant and animal) as it's essential for energy production. In plants, respiration happens continuously, day and night, in mitochondria. While plants produce oxygen during photosynthesis (which only occurs in light), they simultaneously consume oxygen for respiration. Respiration never produces vitamins.

Multiple choice

How are products of photosynthesis transported to all parts of a plant?

  1. Through vessels and sieve tubes

  2. Through sieve tubes and companion cells

  3. Through tracheids and companion cells

  4. Through sieve tubes and parenchyma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In plants, phloem is the tissue responsible for transporting organic nutrients, particularly the products of photosynthesis (sucrose). Phloem consists of sieve tubes (the conducting cells) and companion cells (which provide metabolic support to sieve tube elements). This combination allows efficient transport of sugars from source leaves to sink tissues.

Multiple choice

Red drop and Emerson effect have proved the existence of

  1. Light and dark reactions in photosynthesis

  2. Two distinct photosystems in photosynthesis

  3. The supply of electrons from oxygen evolving complex

  4. Electron transport from water to NADP+ across thylakoids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Red drop (decrease in photosynthetic efficiency at wavelengths >680 nm) and Emerson enhancement effect (greater than additive photosynthesis when beams of 680 nm and shorter wavelengths are combined) demonstrated existence of two photosystems working in series-PSII and PSI.

Multiple choice

Which of the following statements is not correct?

  1. The magnesium atom in chlorophyll a carries the electrons involved in photosynthesis.

  2. Cytochromes are intrinsic proteins of chloroplast's thylakoid membrane.

  3. Ferredoxin has a large positive redox potential and tends to accept electrons.

  4. The phytol tails of chlorophyll a and chlorophyll b are hydrophobic.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The correct answer is 2.

Multiple choice

With reference to photosynthesis, in chloroplasts, consider the following statements:

  1. The reactions that break down water and produce oxygen are located on the lumen side of the thylakoid membrane, in granum areas.
  2. The molecules of ferredoxin-NADP reductase that generate NADPH are located on the side of the membrane facing stroma. Which of the statements given above is/are correct ?

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water-splitting and oxygen evolution occur on lumen side of thylakoid membrane within PSII complexes located in granal stacks. Ferredoxin-NADP reductase (producing NADPH) is bound to stroma-facing side of thylakoid membrane. Both statements correctly describe spatial organization.

Multiple choice

With which of the following is Richmond Lang effect associated?

  1. Stimulation of rosette plants to grow normal

  2. Inhibition of glycolysis by oxygen

  3. Inhibition of photosynthesis by oxygen

  4. Delay of senescence in leaves
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The delay of senescence of leaves and other organs of the plants by cytokinins is called Richmond Lang effect.