🎯Here are exam-focused notes + topic-wise previous year questions (PYQs) & NCERT exercise solution -
1. What are Life Processes?
- Processes that are essential to maintain life in an organism.
- Examples: Nutrition, Respiration, Transportation, Excretion.
2. Nutrition
- Definition: Process of obtaining food & its utilization for energy.
Types:
- Autotrophic Nutrition → Organisms make their own food (e.g., plants).
- Heterotrophic Nutrition → Depend on others for food.
- Saprophytic → On dead matter (fungi)
- Parasitic → On host (tapeworm)
- Holozoic → Ingest → Digest → Absorb (humans)
Photosynthesis:🌞
- Carbon dioxide + Water → Glucose + Oxygen
- 6CO_2 + 6H_2O → C_6H_{12}O_6 + 6O_2
Human Digestive System:
- Mouth → Saliva → Starch breakdown
- Stomach → HCl + pepsin → Proteins
- Small intestine → Enzymes → All food digested
- Large intestine → Water absorption
3. Respiration
- Process of releasing energy from food.
- Glucose + Oxygen → CO₂ + Water + Energy (ATP)
Types:
- Aerobic (with oxygen) — more energy
- Anaerobic (without oxygen) — less energy, produces lactic acid or alcohol.
4. Transportation
In plants:
- Water & minerals → xylem
- Food → phloem (translocation)
In humans:
- Heart → pumps blood
- Arteries → carry oxygenated blood away from heart
- Veins → carry deoxygenated blood toward heart
- Blood → RBCs (O₂), WBCs (immunity), Platelets (clotting), Plasma
5. Excretion
- Removal of metabolic wastes.
In humans:
- Kidneys → Filter urea, excess salts & water
- Ureter → Urine flows to bladder
- Bladder → Stores urine
- Urethra → Urine expelled
In plants:
- Gums, resins, oxygen, CO₂ removed.
🎯 Topic-Wise Previous Year Questions
Very Short Answer (1–2 marks)
- Name the raw materials of photosynthesis.
- What is the function of xylem & phloem?
- Name the excretory unit of kidney.
- Why is oxygen necessary for aerobic respiration?
- Write the equation of photosynthesis.
- Why is transport of materials necessary in organisms?
Short Answer (3 marks)
- How is oxygen & carbon dioxide transported in human beings?
- How does the human heart work as a pump?
- What are the differences between aerobic & anaerobic respiration?
- Draw the structure of nephron & label its parts.
- How do guard cells help in opening & closing of stomata?
Long Answer (5 marks)
- Explain nutrition in amoeba & humans.
- Describe double circulation in humans with diagram.
- Draw the human excretory system & explain its working.
- Write detailed steps of photosynthesis with diagram.
- Describe the process of transportation in plants.
🌟Tips for Exam:
Prepare diagrams:
- Human digestive system
- Nephron
- Human heart
- Stomata
Memorize equations:
- Photosynthesis
- Respiration
Learn differences:
- Arteries vs. veins
- Aerobic vs. anaerobic respiration
- Xylem vs. phloem