Class 10 Science Ch5 Notes Life Processes 2026

Life processes are the activities that keep living organisms alive, helping them grow, reproduce and respond to their environment. For Class 10 students, Chapter 5 Science Life Processes is an important topic that forms the foundation of biology. Our Class 10th Science Life Process Notes break down complex concepts into simple, easy-to-understand points.

Nutrition: How Organisms Obtain Food

Nutrition is the process by which living organisms obtain energy and materials for growth and repair. There are mainly two types of nutrition.

A. Autotrophic Nutrition

• Organisms produce their own food from simple substances.
• Example: Photosynthesis in plants
• Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
• Point to Remember: Plants are “self-sufficient” and produce glucose for energy and growth.

B. Heterotrophic Nutrition

• Organisms depend on others for food.
• Types:

1. Holozoic Nutrition: Ingestion of solid food (humans, animals).
2. Saprophytic Nutrition: Feed on decaying matter (fungi, bacteria).‍
3. Parasitic Nutrition: Feed on host at host’s expense (leeches, tapeworms).

Respiration: Releasing Energy

Respiration is the biochemical process of breaking down food to release energy for life processes. Types are given below:

A. Aerobic Respiration

• Requires oxygen.
• Equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)
• Most efficient, occurs in plants and animals.

B. Anaerobic Respiration

• Occurs without oxygen.
• Produces less energy, with byproducts like alcohol or lactic acid.
• Yeast Equation: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy‍
• Humans: During intense exercise, lactic acid forms, causing muscle fatigue.

Transport: Moving Substances

Transport helps living organisms move nutrients, gases and waste materials to where they are needed. You can think of it as an internal delivery system that keeps everything running smoothly.

In Humans: Circulatory System

In humans, this job is done by the circulatory system. Imagine it like a network of roads. The heart acts as a pump, blood is the delivery vehicle and blood vessels are the roads. 

Red blood cells, with the help of hemoglobin, carry oxygen to all parts of the body. 

Nutrients from the digestive system are delivered to cells, while wastes like carbon dioxide and urea are picked up and removed through the lungs and kidneys.

In Plants: Vascular System

In plants, transport happens through the vascular system. 

Suppose a plant is like a tall building: water and minerals need to be lifted up from the ground. This is done by xylem, which carries water and minerals from roots to leaves. 

The phloem works like a food distribution line, carrying sugars made in the leaves to the rest of the plant.

Excretion: Removing Waste

Excretion is the process of getting rid of waste materials produced in the body. It is like a cleaning system that helps maintain balance and keeps the internal environment healthy (homeostasis).

In Humans

In humans, several organs work together for excretion. The kidneys act like filters, removing wastes such as urea, excess salts and extra water from the blood. 

These wastes leave the body as urine through the ureters, bladder and urethra. The skin also helps by removing water and salts in the form of sweat.

In Plants:

In plants, excretion happens in simpler ways. Plants remove waste products like oxygen, carbon dioxide and excess water during processes such as photosynthesis, respiration and transpiration. Instead of special organs, plants use natural openings and surfaces to get rid of these wastes.

Control and Coordination: Maintaining Balance

Control and coordination help living organisms respond to changes around them and keep their internal processes balanced. It is a smart control system that tells the body or plant what to do and when to do it.

In Humans: Nervous & Hormonal System

Nervous system: Brain, spinal cord, nerves → electrical impulses.

Hormones: Pituitary, thyroid, adrenal → regulate metabolism, growth, reproduction.

In Plants: Plant Hormones

Auxins, Gibberellins, Cytokinins, Ethylene → control growth, flowering, fruiting and response to light/gravity.

Reproduction: Ensuring Species Survival

Reproduction allows organisms to produce offspring and maintain species continuity.

1. Asexual Reproduction

Asexual reproduction involves only one parent and no formation of gametes. It’s like making an exact copy. Examples include binary fission in bacteria, budding in hydra and vegetative propagation in plants like potato and strawberry.

2. Sexual Reproduction

Sexual reproduction involves two parents and the fusion of male and female gametes to form a zygote. This process introduces variation, which is important for evolution. For example, in humans, reproduction occurs when a sperm fuses with an egg during fertilization.

These Ch 5 Science Class 10 Notes make revising life processes simple, quick and stress-free. With clear explanations, diagrams, flowcharts and exam-focused tips, these Class 10 Ch 5 Science Notes cover all the important points you need for scoring well. 

Make sure to use these Class 10 Science Ch Life Process Notes to understand nutrition, respiration, transport, excretion, control and coordination and reproduction in an easy, exam-ready way. Keep them handy, revise smartly and watch your confidence and marks improve!

FAQs

Q1. What are the essential life processes in living organisms?

Ans. The key life processes are nutrition, respiration, transport, excretion, control and coordination and reproduction. 

Q2. How do autotrophic and heterotrophic nutrition differ in plants and animals?

Ans. Autotrophs, like plants, make their own food using sunlight (photosynthesis), whereas heterotrophs, like animals, depend on other organisms for food. 

Q3. What is the importance of the pH scale in digestion and respiration?

Ans. pH affects enzyme activity. In digestion, enzymes like pepsin work best in acidic conditions (stomach), while amylase works in slightly basic conditions (mouth). pH also affects oxygen transport and cellular respiration. 

Q4. Why can diffusion alone not meet the oxygen needs of humans?

Ans. Humans are multicellular and active, so oxygen needs are high. Diffusion is slow and insufficient, so we need a circulatory system to transport oxygen efficiently. 

Q5. What role do enzymes play in digestion - for example, amylase or pepsin?

Ans. Enzymes speed up chemical breakdown of food. Amylase breaks starch into sugar, while pepsin breaks proteins into peptides.

Q6. How is transport of substances in plants different from that in humans?

Ans. Plants use xylem and phloem to move water, minerals and sugars, mostly passively or via pressure. Humans use a circulatory system with blood, heart and vessels to actively transport oxygen, nutrients and waste. 

Q7. Why is excretion vital in maintaining life processes?

Ans. Excretion removes toxic metabolic wastes like urea, CO₂ and excess water. Without it, cell function would be impaired and life processes would fail.