Study the following and pick up the correct statements

I) A mycorrhiza is a symbiotic association of a fungus with a root system.

II) The water loss through the leaves of plants in its liquid phase is called guttation.

III) Transpiration occurs mainly through the stomata in the leaves.

IV) No energy is required for diffusion.

Key Points

• Statement I: A mycorrhiza is indeed a symbiotic association between a fungus and plant roots, where the fungus helps the plant absorb nutrients and water, and the plant provides carbohydrates to the fungus.
• Statement II: Guttation is the loss of water in liquid form from the edges of leaves, typically through specialized structures known as hydathodes.
• Statement III: Transpiration, the loss of water vapor from plant surfaces, primarily occurs through stomata present on leaves.
• Statement IV: Diffusion, the movement of molecules from a region of higher concentration to a region of lower concentration, is a passive process that does not require energy.

Important Points

• Symbiosis: The mutual benefit derived in mycorrhizal associations is a classic example of symbiosis in nature.
• Guttation vs. Transpiration: Guttation involves liquid water, while transpiration involves water vapor.
• Energy in Diffusion: Diffusion is a passive process driven by the concentration gradient, unlike active transport which requires energy.

Additional Information

• Mycorrhiza:
  • Fungi in mycorrhizal associations significantly increase the surface area for water and nutrient absorption.
  • There are two main types: ectomycorrhiza (outside root cells) and endomycorrhiza (inside root cells).
• Guttation:
  • Occurs under conditions of high soil moisture and low transpiration rates (e.g., at night).
  • It is commonly observed in plants like grasses, strawberries, and tomatoes.
• Transpiration:
  • It helps in cooling the plant, maintaining the flow of minerals, and water uptake.
  • Transpiration rates are affected by factors like light, temperature, humidity, and wind.
• Diffusion:
  • Diffusion is critical for gas exchange in plants, such as oxygen and carbon dioxide during photosynthesis and respiration.
  • It also plays a role in the movement of nutrients and ions across cell membranes.