Free Plant Nutrition and Transport MCQs with Answers

71. The attraction between water molecules and the cell wall of xylem is termed as:

• A. Cohesion
• B. Tension
• C. Adhesion
• D. Imbibition

Explanation: Option A: Cohesion refers to the attraction between water molecules themselves, which allows them to stick together and form a continuous column in the xylem. Option B: Tension refers to the force that pulls water up through the xylem, which is caused by transpiration at the leaves. Option C: Adhesion is a molecular attraction between "unlike" molecules. In the case of the xylem, adhesion occurs between water molecules and the molecules of the xylem cell walls. Cohesion is a molecular attraction between "like" molecules. In water, cohesion occurs due to hydrogen bonding between the water molecules.Option D: Imbibition refers to the process by which a solid absorbs water, such as a seed swelling when it takes up water.

72. Which of the following pigments is Blue-green in colour?

• A. Chlorophyll a
• B. Chlorophyll b
• C. Chlorophyll c
• D. None of these

Explanation: Chlorophyll a is the most abundant pigment in plants and algae. It is a blue-green pigment that absorbs blue and red light during photosynthesis. Chlorophyll a is responsible for the overall green color of plants.

73. What is reduced in photosynthesis?

• A. Oxygen
• B. Carbon dioxide
• C. Water
• D. Light

Explanation: Correct option is B. During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose.

74. Chlorophylls are found embedded in the _ membrane?

• A. Stroma
• B. Grana
• C. Thylakoid
• D. Intergrana

Explanation: The correct answer for this is "Thylakoid". Since chlorophyll is a pigment present in the chloroplast, It is present and embedded in the "thylakoid" membrane present in "Stroma".

75. Name the external factor of growth in plants.

• A. Carbon dioxide.
• B. Water.
• C. Hormones.
• D. Nutrition.

Explanation: Environmental factors that affect plant growth include light, temperature, water, and humidity.

76. The dew drops on tips of grass leaves is an example of:

• A. Infestation.
• B. Exudation.
• C. Bleeding.
• D. Imbibition.

Explanation: Closely associated with root pressure is a phenomenon called guttation or exudation. It is the loss of liquid water through water secreting glands or hydrathodes.

77. Chlorophylls absorb mainly _ wave length.

• A. Yellow.
• B. Violet-blue.
• C. Green.
• D. Indigo.

Explanation: All plants have chlorophyll a which absorbs most strongly at ~450 nm, or a bright blue color.

78. _ did not have the adaptations to remove the flooding of their cells in fresh water.

• A. Both B, D.
• B. Hydrophytes
• C. None of B, D.
• D. Xerophytes.

Explanation: Xerophytes are plants adapted to arid or dry environments. They have adaptations to conserve water and tolerate drought conditions. Since they are not present in freshwater so, they don't have adaptations to remove the flooding of their cells.

79. _ is necessary for development of leaves and it tends to accumulate in leaves and bark.

• A. NO2
• B. Calcium
• C. Gypsum
• D. Nitrogen

Explanation: d) Nitrogen: This is the correct option. Nitrogen is necessary for the development of leaves and is a critical component of chlorophyll, which is essential for photosynthesis. Nitrogen tends to accumulate in leaves, as it is a major component of proteins and other cellular structures. However, it does not specifically accumulate in bark.

80. During photorespiration, the glycolate is converted into glycine in a structure of ceil called:

• A. Golgi Bodies
• B. Mitochondria
• C. Glyoxysome
• D. Peroxisome

Explanation: Explanation:In the Peroxisomes, glycolate is oxidized with O2 uptake to glyoxylate by glycolate oxidase, and the glyoxylate is converted to glycine by glutamate glyoxylate amino-transferase.This option is not correct. Golgi bodies are organelles involved in processing and sorting proteins and lipids in eukaryotic cells. This option is also incorrect because mitochondria are organelles responsible for producing ATP through cellular respiration, which occurs in the presence of oxygen. Glyoxisome is an organelle found in plant cells that is involved in lipid metabolism, particularly in the conversion of stored lipids into carbohydrates. It is not directly involved in the process of photorespiration.