Class 10 Science Notes – Life Processes (CBSE
2025)
1. What are Life Processes?
All living organisms perform basic functions such as nutrition, respiration, transportation, and
excretion to maintain life. These are called life processes.
2. Nutrition
Nutrition is the process of obtaining and using food.
Types of nutrition:
1. Autotrophic – Organisms make their own food (e.g., plants). Process: Photosynthesis.
Equation: 6CO■ + 6H■O → C■H■■O■ + 6O■ (in presence of sunlight and chlorophyll)
2. Heterotrophic – Organisms depend on others for food (e.g., animals, humans).
Human digestive system parts: Mouth → Oesophagus → Stomach → Small intestine → Large
intestine → Anus
3. Respiration
Respiration is the process of breaking down food to release energy.
Types:
- Aerobic respiration: in presence of oxygen
C■H■■O■ + 6O■ → 6CO■ + 6H■O + Energy
- Anaerobic respiration: without oxygen (e.g., yeast → alcohol + CO■)
Organs in humans: Nasal cavity → Trachea → Lungs → Alveoli.
4. Transportation
In Plants: Xylem transports water & minerals upward; Phloem transports food in both directions.
In Humans: Blood circulates through heart, arteries, veins, capillaries.
Main parts: Heart, Blood vessels, Blood. Heart has 4 chambers – Left & Right atrium, Left & Right
ventricle.
5. Excretion
Removal of metabolic waste from the body. Human excretory system: Kidneys, ureters, urinary
bladder, urethra. Main waste: Urea.
Important Points:
• Photosynthesis is both anabolic and endothermic.
• Human heart beats ~72 times/min.
• Nephron is the structural and functional unit of the kidney.
• Blood has plasma, RBC, WBC, platelets.
2025)
1. What are Life Processes?
All living organisms perform basic functions such as nutrition, respiration, transportation, and
excretion to maintain life. These are called life processes.
2. Nutrition
Nutrition is the process of obtaining and using food.
Types of nutrition:
1. Autotrophic – Organisms make their own food (e.g., plants). Process: Photosynthesis.
Equation: 6CO■ + 6H■O → C■H■■O■ + 6O■ (in presence of sunlight and chlorophyll)
2. Heterotrophic – Organisms depend on others for food (e.g., animals, humans).
Human digestive system parts: Mouth → Oesophagus → Stomach → Small intestine → Large
intestine → Anus
3. Respiration
Respiration is the process of breaking down food to release energy.
Types:
- Aerobic respiration: in presence of oxygen
C■H■■O■ + 6O■ → 6CO■ + 6H■O + Energy
- Anaerobic respiration: without oxygen (e.g., yeast → alcohol + CO■)
Organs in humans: Nasal cavity → Trachea → Lungs → Alveoli.
4. Transportation
In Plants: Xylem transports water & minerals upward; Phloem transports food in both directions.
In Humans: Blood circulates through heart, arteries, veins, capillaries.
Main parts: Heart, Blood vessels, Blood. Heart has 4 chambers – Left & Right atrium, Left & Right
ventricle.
5. Excretion
Removal of metabolic waste from the body. Human excretory system: Kidneys, ureters, urinary
bladder, urethra. Main waste: Urea.
Important Points:
• Photosynthesis is both anabolic and endothermic.
• Human heart beats ~72 times/min.
• Nephron is the structural and functional unit of the kidney.
• Blood has plasma, RBC, WBC, platelets.
