Nutrition in Plants and Animals: Biology for Class 10
Fuel for Life
Just as a car needs petrol, living organisms need energy to maintain order and perform life processes. Nutrition is the process of intake of nutrients (carbohydrates, fats, proteins, etc.) and their utilization by an organism.
1. Autotrophic Nutrition (Self-Feeding)
Organisms that synthesize their own food from inorganic substances (CO₂, Water).
- Who? Green plants and some bacteria.
- How? By Photosynthesis. (Check out our detailed article on Photosynthesis!)
2. Heterotrophic Nutrition (Other-Feeding)
Organisms that depend on others for food.
Holozoic
Ingesting solid food. (e.g., Humans, Amoeba).
Saprotrophic
Feeding on dead/decaying matter. (e.g., Fungi/Bread Mould).
Parasitic
Living inside/on a host without killing it. (e.g., Lice, Tapeworm, Cuscuta).
Human Digestive System
"Digestion is the breakdown of complex insoluble food molecules into simple soluble ones."
Teeth crush food. Salivary Amylase breaks Starch → Sugar.
Pepsin breaks Protein. HCl kills germs & activates Pepsin. Mucus protects lining.
Small Intestine:
Site of Complete Digestion. Villi increase surface area for absorption.
Exam Focus & NCERT
Biology answers require keywords. Missing keywords like "Villi" or "Peristalsis" will lose you marks.
1
Function Questions (3 Marks)
"What is the role of Acid in our stomach?" (1. Kill bacteria, 2. Acidic medium for Pepsin).
2
Diagram Based (5 Marks)
"Draw the Human Alimentary Canal and label: Liver, Pancreas, Gall Bladder."
Practice Questions
Q1. MCQ
The breakdown of Pyruvate occurs in?
a) Cytoplasm b) Mitochondria c) Chloroplast
Q2. Reasoning
Why is the small intestine in herbivores longer than in carnivores?
Conclusion
Nutrition is the first step of life. Understanding how we extract energy from a simple piece of bread involves a complex chemical factory running inside us. Biology is amazing!
Visual Learners?
See the digestion process in 3D animation to never forget the sequence.