Revision Notes: Basic Biology | Biology Class 10 ICSE PDF Download

Biology is the study of living things and how they function.

1. Cellular Structure

• All living things are made up of cells.
• Protoplasm gives cells their shape.

2. Metabolism

• Metabolism includes anabolism (building up ) and catabolism (breaking down ).

3. Growth, Repair, and Regeneration

• Growth adds new protoplasmic material and is permanent and irreversible.
• Repair replaces worn-out cells and heals injuries.
• Some organisms can regenerate body parts, like lizards regrowing their tails.

4. Respiration

• Respiration is a catabolic process where organisms take in oxygen, oxidize organic substances, and release carbon dioxide, water vapor, and energy.

5. Movement

• Movement is any change in the position of a body part.
• For example, plants grow roots away from light, while stems, leaves, and flowers grow towards light.
• Amoeba moves by extending pseudopodia.

6. Nutrition

• Nutrition is the process of taking in food and using it for growth and tissue replacement.
• Feeding, digestion, and assimilation are parts of nutrition.
• Green plants make their food through photosynthesis, using carbon dioxide and water in the presence of sunlight.

7. Excretion

• Excretion is the removal of harmful waste products produced by the organism's metabolism.

8. Irritability

• A stimulus is any change in the environment that an organism responds to.
• Irritability is the ability of an organism to respond to stimuli in a specific way, such as plants responding to light and gravity.

9. Reproduction and Evolution

• Living organisms can produce new individuals that resemble them in essential characteristics.

10. Life Span and Death

• Life span is the period during which an organism completes its life cycle.

Differences between Living and Non-living Things

Living Things:

• Cellular Organization: All living things are made up of cells, which are the basic units of life.
• Growth: Living organisms grow in size or complexity over time.
• Reproduction: They have the ability to reproduce, either sexually or asexually.
• Metabolism: Living things carry out chemical reactions, such as breaking down food for energy (respiration) and building substances (synthesis).
• Response to Stimuli: Living organisms can respond to changes in their environment, like light, temperature, or pressure.
• Adaptation: Over generations, living things can adapt to their surroundings through evolution.
• Homeostasis: Living things can maintain a stable internal environment, despite changes in external conditions.
• Movement: While not all living things move in the same way, most can move, or at least parts of their body (e.g., plants grow toward light).

Non-Living Things:

• No Cellular Organization: Non-living things don’t have cells or any organized structure like living organisms.
• No Growth: They do not grow or develop; they remain the same size or shape unless altered externally.
• No Reproduction: Non-living things cannot reproduce on their own.
• No Metabolism: They do not engage in chemical reactions for energy or synthesis.
• No Response to Stimuli: Non-living things do not respond to changes in their environment in a biological sense.
• No Adaptation: Non-living things don’t evolve or change to adapt over time (though they can be altered by external forces).
• No Homeostasis: Non-living things do not maintain a stable internal environment.
• No Movement: Non-living things do not move on their own, although they can be moved by external forces.

Differences between the Growth of a Living Organism and the Growth of a Crystal

Growth of a Living Organism

• Growth occurs by cell division.
• Growth is irreversible.

Growth of a Crystal

• Growth occurs by the addition of similar material.
• Growth is reversible.