Class 7 Science - ICSE-BIOLOGY
Nutrition
The chapter Nutrition in ICSE Class 7 Biology explores how living organisms obtain and utilize food for energy, growth, and repair. Students will learn about the different modes of nutrition, focusing heavily on heterotrophic nutrition in animals like amoeba and humans, and autotrophic nutrition in plants through photosynthesis. The chapter details the human digestive system, highlighting the role of various organs and digestive juices in breaking down complex food into simpler substances. For board and school exams, this chapter is crucial as it builds the foundational concepts of physiology, commonly featuring diagram-based questions and process explanations.
Start Learning FreeKey Concepts
Autotrophic Nutrition
A mode of nutrition where organisms, such as green plants, make their own food from simple inorganic substances like carbon dioxide and water in the presence of sunlight.
Heterotrophic Nutrition
A mode of nutrition where organisms cannot make their own food and depend directly or indirectly on plants, divided into holozoic, parasitic, saprophytic, and symbiotic types.
Photosynthesis
The process by which green plants trap solar energy using chlorophyll to convert carbon dioxide and water into glucose and release oxygen.
Holozoic Nutrition
A type of heterotrophic nutrition involving the ingestion of solid food, followed by digestion, absorption, assimilation, and egestion, as seen in humans and amoeba.
Human Digestive System
A complex canal starting from the mouth and ending at the anus, consisting of the alimentary canal and associated digestive glands that process food step-by-step.
Important Formulas
Board Exam Info
In ICSE Biology Class 7 exams, this chapter typically carries around 8 to 12 marks. Questions frequently include labeling diagrams of the human digestive system or Amoeba, defining key biological terms, and explaining the steps of nutrition or photosynthesis.
Frequently Asked Questions
What is the difference between autotrophic and heterotrophic nutrition?
Autotrophs can prepare their own food using sunlight and inorganic matter, whereas heterotrophs depend on other organisms for their nourishment.
Why is the small intestine the main site of digestion in humans?
The small intestine receives digestive secretions from the liver and pancreas, and its walls secrete intestinal juice, which completely digests carbohydrates, fats, and proteins.
What are villi and what is their function?
Villi are finger-like projections on the inner walls of the small intestine that increase the surface area for the absorption of digested food.
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