Notes - Life Processes - Class 10

Life Processes

Overview: Nutrition, Respiration, Transportation, and Excretion in Plants & Animals.

1. Nutrition

Autotrophic: Plants make food using Photosynthesis.

6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O

Heterotrophic: Animals depend on others. (Holozoic, Saprophytic, Parasitic).

Human Digestion: Mouth (Amylase) → Oesophagus → Stomach (HCl, Pepsin) → Small Intestine (Villi, Trypsin, Lipase) → Large Intestine.

2. Respiration

Aerobic: In presence of O₂. Releases more energy. (Mitochondria). End products: CO₂, H₂O, Energy.
Anaerobic: In absence of O₂. (Yeast - Ethanol + CO₂; Muscle cells - Lactic Acid).

3. Transportation

Humans: Heart (Double circulation), Arteries (Oxygenated), Veins (Deoxygenated), Capillaries. Blood (RBC, WBC, Platelets).

Plants: Xylem (Water & Minerals), Phloem (Food - Translocation).

4. Excretion

Humans: Kidney (Nephrons) → Ureter → Urinary Bladder → Urethra. Removal of nitrogenous waste (Urea).

Plants: Transpiration, falling leaves, resins and gums.

NCERT In-Text Questions (Solved)

Page 95

Q1. Why is diffusion insufficient for multicellular organisms like humans?

Diffusion is slow. In multicellular organisms, all cells are not in direct contact with environment. Diffusion cannot meet oxygen requirement of all body cells quickly.

Q2. Criteria to decide if something is alive?

Visible movements (locomotion) and invisible molecular movements (growth, respiration, repair).

Q3. Outside raw materials used by organism?

Food (source of energy), Oxygen (for breakdown of food), Water (for proper functioning).

Q4. Processes essential for maintaining life?

Nutrition, Respiration, Transportation, Excretion.

Page 101

Q1. Difference between Autotrophic and Heterotrophic nutrition.

Autotrophic: Organism prepares own food from inorganic raw materials (CO₂, H₂O). Eg: Green plants.
Heterotrophic: Organism depends on others for food. Eg: Animals, Fungi.

Q2. Where do plants get raw materials for Photosynthesis?

CO₂ from Air, Water from Soil, Energy from Sunlight. Chlorophyll trap sunlight.

Q3. Role of acid in stomach?

1. Kills bacteria entering with food.
2. Creates acidic medium for enzyme Pepsin to act (digestion of proteins).

Q4. Function of Digestive Enzymes?

Break down complex insoluble food molecules into simple soluble molecules (Carbs to Glucose, Proteins to Amino acids, Fats to Fatty acids).

Q5. How is small intestine designed to absorb food?

It has millions of finger-like projections called Villi which increase surface area for absorption. They are rich in blood vessels.

Page 105

Q1. Possible pathways of glucose breakdown.

1. Aerobic (in Mitochondria): CO₂ + H₂O + Energy.
2. Anaerobic (in Yeast): Ethanol + CO₂ + Energy.
3. Lack of Oxygen (in Muscle): Lactic Acid + Energy.

Q2. Why aquatic animals breathe faster?

Amount of dissolved oxygen in water is much lower than amount of oxygen in air. To get sufficient oxygen, they breathe faster.

Q3. How is Oxygen and CO2 transported in humans?

Oxygen: Carried by Hemoglobin in RBCs.
CO₂: Mostly dissolved in blood plasma (as it is more soluble in water).

Q4. Design of lungs for gas exchange.

Bronchioles terminate in balloon-like structures called Alveoli. Alveoli provide vast surface area and have extensive network of blood capillaries for exchange of gases.

Page 110

Q1. Components of transport system in humans and function?

Heart (Pumps blood), Blood (Transport medium), Blood Vessels (Arteries/Veins).

Q2. Why essential to separate oxygenated and deoxygenated blood?

To efficiently supply oxygen to body. Humans/Birds are warm-blooded and need high energy to maintain body temperature. Separation ensures high efficiency.

Q3. Components of transport system in plants?

Xylem: Transports water and minerals from roots to leaves.
Phloem: Transports food (sucrose) from leaves to other parts.

Q4. How are water and minerals transported in plants?

Through Xylem vessels/tracheids. Root pressure and Transpiration pull (suction force) helps in upward movement.

Q5. How is food transported in plants?

Through Phloem (Sieve tubes with companion cells). It utilizes energy (ATP) to create osmotic pressure which moves material from high to low pressure (Translocation).

Page 112

Q1. Structure and functioning of Nephron.

Nephron is filtration unit of kidney. Has Bowman's capsule, Glomerulus, Tubular part. It filters blood, reabsorbs useful substances (glucose, water) and collects urine.

Q2. Methods of excretion in plants.

Transpiration (water loss), Storing waste in vacuoles, Falling leaves, Resins/Gums in old xylem, Excreting into soil.

Q3. How is amount of urine produced regulated?

Depends on amount of excess water in body and amount of soluble waste to be excreted. (Controlled by ADH hormone).

Exercise Solutions - Life Processes - Class 10

NCERT Exercise Questions

Complete solutions for Chapter 5 exercises.

Q1. Kidneys in humans are part of which system?

(c) Excretion.

Q2. Xylem in plants are responsible for?

(a) Transport of water.

Q3. Autotrophic mode requires?

(d) All of the above (CO₂ and water, Chlorophyll, Sunlight).

Q4. Breakdown of pyruvate to give CO2, water and energy takes place in?

(b) Mitochondria (Aerobic respiration).

Q5. How are fats digested in our bodies? Where?

Where: Small Intestine.
Process: Bile juice from liver emulsifies large fat globules into smaller ones. Enzyme Lipase (from pancreas) breaks them down into fatty acids and glycerol.

Q6. Role of Saliva?

Moistens food. Contains enzyme Salivary Amylase which breaks down starch (complex carb) into sugar (maltose).

Q7. Condition for autotrophic nutrition and by-products?

Conditions: Sunlight, Chlorophyll, CO₂, Water.
By-products: Oxygen (O₂). Main product is Carbohydrate (Glucose).

Q8. Difference Aerobic/Anaerobic respiration? Organisms?

Aerobic: Uses O₂, End products CO₂+H₂O, High Energy. (Humans, Plants).
Anaerobic: No O₂, End products Alcohol/Lactic Acid, Low Energy. (Yeast, Bacteria).

Q9. How are alveoli designed?

Balloon-like structures. Thin walls. Richly supplied with blood capillaries to facilitate diffusion of gases (O₂ in, CO₂ out). Large surface area.

Q10. Consequence if Haemoglobin is deficient?

Anemia. Less oxygen supply to body cells. Results in fatigue, weakness, breathlessness.

Q11. Double circulation? Why necessary?

Blood goes through heart twice in one cycle (Pulmonary + Systemic). Necessary to separate oxygenated/deoxygenated blood for high energy supply in warm-blooded animals.

Q12. Xylem vs Phloem transport?

Xylem: Water/Minerals. One direction (Up). Physical forces (Transpiration pull).
Phloem: Food. Both directions. Uses Energy (Active transport).

Q13. Compare alveoli and nephron.

Alveoli (Lungs): Functional unit of Respiration. Exchange of gases. Thin wall. Capillaries.
Nephron (Kidney): Functional unit of Excretion. Filtration of blood. Bowman's capsule/Tubule.

Formulas & Facts - Life Processes - Class 10

Key Processes & Facts

Short notes on biological functions and definitions.

Important Biological Equations

Photosynthesis 6CO₂ + 12H₂O → Glucose + 6O₂

Aerobic Resp. Glucose → CO₂ + H₂O + 38 ATP

Anaerobic (Yeast) Glucose → Ethanol + CO₂ + 2 ATP

Anaerobic (Muscle) Glucose → Lactic Acid + 2 ATP

50 Important Facts

1. Life processes: Maintenance functions of living organisms.

2. Nutrition: Process of obtaining food.

3. Autotrophs make their own food (Green plants).

4. Heterotrophs depend on others for food.

5. Chlorophyll captures light energy.

6. Stomata are tiny pores for gas exchange.

7. Guard cells control opening/closing of stomata.

8. Parasites derive food from host without killing.

9. Amoeba uses pseudopodia to engulf food.

10. Saliva contains salivary amylase.

11. Amylase breaks starch into sugar.

12. Oesophagus moves food by peristalsis.

13. Stomach releases HCl, Pepsin, Mucus.

14. Pepsin digests protein in acidic medium.

15. Mucus protects stomach lining from acid.

16. Small intestine is site of complete digestion.

17. Liver secretes Bile juice.

18. Bile emulsifies fats (Large globules to small).

19. Pancreas secretes Trypsin and Lipase.

20. Villi increase surface area for absorption.

21. Large intestine absorbs water.

22. Respiration releases energy from food.

23. ATP is energy currency of cell.

24. Glycolysis occurs in Cytoplasm (Glucose to Pyruvate).

25. Krebs cycle occurs in Mitochondria.

26. Alveoli are balloon like structures in lungs.

27. Alveoli increase surface area for gas exchange.

28. Haemoglobin carries Oxygen in blood.

29. Plasma transports CO2 and waste.

30. Human heart has 4 chambers.

31. Ventricles have thicker walls than atria.

32. Arteries carry blood away from heart.

33. Veins carry blood towards heart.

34. Capillaries are one-cell thick vessels.

35. Platelets help in blood clotting.

36. Lymph is also called tissue fluid.

37. Transpiration helps in absorption of water.

38. Translocation is transport of food.

39. Xylem tissue consists of vessels & tracheids.

40. Phloem consists of sieve tubes & companion cells.

41. Kidney filters nitrogenous waste (Urea).

42. Nephron is filtration unit of kidney.

43. Glomerulus is a cluster of capillaries.

44. Bowman's capsule collects filtrate.

45. Useful substances are reabsorbed in tubule.

46. Urine is stored in Urinary Bladder.

47. Urethra releases urine.

48. Plants excrete O2 during photosynthesis.

49. Plants excrete CO2 during respiration at night.

50. Plants shed leaves to get rid of wastes.

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