Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Nutrition is the mode of taking food by an organism and its utilization by the body.
Autotrophic Nutrition: The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic nutrition. Green plants are called autotrophs because they prepare food using , , and minerals.
Photosynthesis: It is the process by which green plants synthesize their own food (glucose) using and in the presence of sunlight and chlorophyll. The chemical reaction releases as a byproduct.
Chlorophyll: The green pigment found in the leaves of plants that helps capture the energy of sunlight to drive the process of photosynthesis.
Stomata: Tiny pores present on the surface of leaves through which exchange of gases like and occurs. They are surrounded by 'guard cells'.
Heterotrophic Nutrition in Plants: Plants that do not have chlorophyll and depend on food produced by other plants. This includes Parasites (e.g., ), Saprotrophs (e.g., Fungi), and Insectivorous plants (e.g., Pitcher plant).
Symbiotic Relationship: Some organisms live together and share both shelter and nutrients. For example, in Lichens, an alga (autotroph) and a fungus (saprotroph) live together.
📐Formulae
💡Examples
Problem 1:
Explain why leaves are called the 'food factories' of plants and identify the gas consumed during the process.
Solution:
Leaves contain which traps solar energy to convert and into . The gas consumed is .
Explanation:
Synthesis of food occurs in leaves; therefore, all raw materials must reach the leaf. from the air is taken in through stomata.
Problem 2:
During an experiment, a student covers a leaf with black paper. After 48 hours, they perform an iodine test. What will be the observation?
Solution:
The covered part of the leaf will not turn blue-black, indicating the absence of starch ( storage).
Explanation:
Since sunlight was blocked, photosynthesis could not occur in the covered area, and no starch was produced.