🔥 Chapter 5: Life Processes

🎯 Class 10 Science Best Notes (With Hindi Explanation)

🌱 1. What are Life Processes?

Life processes are the basic activities performed by living organisms to stay alive such as nutrition, respiration, transportation, and excretion.
👉 Hindi Explanation: Life processes wo zaroori kriyayein hoti hain jo jeevit rehne ke liye har jeev karta hai jaise ki poshan, swasan, parivahan aur nikas.

🍛 2. Nutrition

Nutrition is the process by which organisms obtain food and utilize it to get energy.
🔹 Types of Nutrition:

Autotrophic: Organisms make their own food. (e.g., plants)
Heterotrophic: Organisms depend on others for food. (e.g., humans)

👉 Hindi Explanation:
Nutrition ek aisi prakriya hai jisme jeev apna bhojan prapt karte hain aur usse energy banate hain.

🌿 Autotrophic Nutrition (Photosynthesis)

Photosynthesis: Process by which green plants prepare food using sunlight, CO₂, and water.
🔹 Equation:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in presence of sunlight and chlorophyll)
👉 Hindi: Photosynthesis mein paudhe suraj ki roshni, CO₂ aur paani ka use karke apna bhojan banate hain.

🍽️ Heterotrophic Nutrition

Types:

Holozoic (Human)
Saprophytic (Fungi)
Parasitic (Cuscuta, Tapeworm)

👉 Hindi: Heterotrophic jeev doosron par bhojan ke liye nirbhar hote hain.

🫁 3. Respiration

Respiration is the process of releasing energy from food.
🔹 Types:

Aerobic: With oxygen
Anaerobic: Without oxygen

🔹 Equation (Aerobic):
Glucose + O₂ → CO₂ + H₂O + Energy

👉 Hindi: Respiration mein bhojan se energy milti hai jo jeev ke kaam aati hai.

🚚 4. Transportation

It is the movement of food, water, and nutrients in the body.
🔹 In Humans:

Blood circulatory system (Heart, Blood, Blood vessels)
Heart has 4 chambers: 2 atria, 2 ventricles
Double circulation: Blood passes through heart twice in one cycle.

🔹 In Plants:

Xylem: Water transport
Phloem: Food transport

👉 Hindi: Transportation ek aisi kriya hai jisme sharir ke alag-alag hisson mein paani, bhojan aur gas ka parivahan hota hai.

🚽 5. Excretion

Excretion is the removal of metabolic waste from the body.
🔹 In Humans: Kidneys remove urea (through urine)
🔹 In Plants: Waste stored in leaves, resins, gum etc.

👉 Hindi: Excretion wo prakriya hai jisme sharir ke andar bane harmful padarthon ko bahar nikala jata hai.

📘 Important Questions for Practice — With Answers

✅ 1 Mark Questions

What is the function of xylem in plants?
👉 Transport of water and minerals.
Define excretion.
👉 Removal of metabolic waste from the body.
Name the pigment required for photosynthesis.
👉 Chlorophyll.

✅ 2 Mark Questions

Differentiate between autotrophic and heterotrophic nutrition.
👉
Autotrophic: Organism makes its own food (e.g. Plants)
Heterotrophic: Depends on others for food (e.g. Humans)
Why is transportation important in plants and animals?
👉 To supply nutrients and remove waste products efficiently to/from all parts of the body.
What is double circulation?
👉 Blood passes twice through the heart in one complete cycle — once for oxygenation and once for delivery.

✅ 3 Mark Questions

Explain the process of photosynthesis with equation.
👉 Photosynthesis is the process by which green plants prepare food using sunlight, carbon dioxide, and water.
Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Describe how food is digested in human beings.
👉 Digestion starts in mouth (saliva), continues in stomach (HCl, pepsin), and completes in small intestine with enzymes from liver and pancreas.
Write the differences between aerobic and anaerobic respiration.
👉

Aerobic: Uses oxygen, more energy, CO₂ + H₂O formed
Anaerobic: No oxygen, less energy, alcohol or lactic acid formed

✅ 5 Mark Questions

Explain the human circulatory system.
👉

It includes heart, blood, and blood vessels.
Heart pumps oxygenated and deoxygenated blood separately.
Arteries carry blood away from the heart, veins bring it back.
Capillaries allow exchange of substances.
Ensures oxygen and nutrients reach cells.

Describe the human excretory system.
👉

Main organ: Kidney
Ureters carry urine from kidneys to urinary bladder
Urinary bladder stores urine
Urethra expels urine out of body
Kidneys filter urea and excess water from blood.

Life Processes – Questions

1. Define life processes.

Answer: The processes like respiration, digestion, etc., which together keep the living organisms alive and perform the job of body maintenance, are called life processes.

2. Name any four basic life processes.

Answer: Digestion, respiration, circulation, and excretion.

3. What is nutrition?

Answer: Nutrition is the whole process by which an organism obtains its food.

4. Differentiate between autotrophs and heterotrophs.

Answer:

| Autotrophs | Heterotrophs | |------------|---------------| | Organisms that can make their own food. | Organisms that depend on plants or other animals for food. |

5. How do plants obtain nutrition?

Answer: Plants are autotrophs, so they make their own food through the process of photosynthesis.

6. Why do animals depend on other organisms for food?

Answer: Animals are heterotrophs and cannot make their own food, so they depend on plants or other animals.

1. Define autotrophic nutrition. Give one example.

Answer: Autotrophic nutrition is the mode of nutrition in which organisms use inorganic substances like CO₂ and water to make food through photosynthesis.

Example: Green plants.

2. Define heterotrophic nutrition. Give one example.

Answer: Heterotrophic nutrition is the mode of nutrition in which organisms cannot make their own food and depend on other organisms for it.

Example: Animals, fungi.

3. Write the chemical equation for photosynthesis.

Answer:

6CO₂ + 12H₂O ⟶ (Sunlight, Chlorophyll) ⟶ C₆H₁₂O₆ + 6O₂ + 6H₂O.

4. Name the raw materials required for photosynthesis.

Answer:

Sunlight

Chlorophyll

Carbon dioxide (CO₂)

Water (H₂O)

5. What is the site of photosynthesis in a plant cell?

Answer: Photosynthesis takes place in the chloroplasts of the leaf, which contain chlorophyll.

6. Mention the main events of photosynthesis.

Answer:

Absorption of light energy by chlorophyll

Conversion of light energy into chemical energy

Splitting of water into hydrogen and oxygen

Reduction of CO₂ into carbohydrates

7. What are stomata? Mention two functions.

Answer: Stomata are tiny pores on the surface of leaves.

Functions:

(a) Exchange of gases (O₂/CO₂)

(b) Loss of water vapour during transpiration

8. Differentiate between autotrophs and heterotrophs. (2 Marks)

| Autotrophs | Heterotrophs | |----------------|------------------| | Make their own food using CO₂, water, and sunlight. | Depend on autotrophs or other organisms for food. | | Example: Green plants | Example: Animals, fungi |

1. Define autotrophic nutrition. Give one example.

Answer: Autotrophic nutrition is the mode of nutrition in which organisms use inorganic substances like CO₂ and water to make food through photosynthesis.

Example: Green plants.

2. Define heterotrophic nutrition. Give one example.

Answer: Heterotrophic nutrition is the mode of nutrition in which organisms cannot make their own food and depend on other organisms for it.

Example: Animals, fungi.

3. Write the chemical equation for photosynthesis.

Answer:

6CO_2 + 12H_2O \xrightarrow{\text{Sunlight, Chlorophyll}} C_6H_{12}O_6 + 6O_2 + 6H_2O

4. Name the raw materials required for photosynthesis.

Answer:

Sunlight

Chlorophyll

Carbon dioxide (CO₂)

Water (H₂O)

5. What is the site of photosynthesis in a plant cell?

Answer: Photosynthesis takes place in the chloroplasts of the leaf, which contain chlorophyll.

6. Mention the main events of photosynthesis.

Answer:

Absorption of light energy by chlorophyll

Conversion of light energy into chemical energy

Splitting of water into hydrogen and oxygen

Reduction of CO₂ into carbohydrates

7. What are stomata? Mention two functions.

Answer: Stomata are tiny pores on the surface of leaves.

Functions:

(a) Exchange of gases (O₂/CO₂)

(b) Loss of water vapour during transpiration

Short Answer Questions (2–3 Marks)

5. List the steps involved in nutrition in Amoeba.

Answer:

(i) Ingestion – Food is taken in using pseudopodia.

(ii) Digestion – Food is broken down inside the food vacuole.

(iii) Absorption – Nutrients are absorbed into the cytoplasm.

(iv) Assimilation – Absorbed nutrients are used for energy and growth.

(v) Egestion – Undigested food is thrown out.

6. Differentiate between ingestion and egestion.

Answer:

Ingestion Egestion

Taking in food into the body. Removal of undigested food from the body.

7. Explain how Paramecium takes its food.

Answer: Paramecium uses cilia (tiny hair-like structures) to move food to a specific spot in the cell, where it is ingested.

8. Mention the five steps of nutrition in heterotrophs.

Answer:

(i) Ingestion – Intake of food

(ii) Digestion – Breakdown into simpler substances

(iii) Absorption – Movement of nutrients into the body

(iv) Assimilation – Utilisation of nutrients

(v) Egestion – Removal of waste

1. What is the function of peristaltic movement?

Answer: Peristaltic movement pushes food through the oesophagus to the stomach by rhythmic contraction and relaxation of muscles.

2. Name the three components of gastric juice.

Answer: Pepsin, Hydrochloric acid (HCl), and Mucus.

3. What is the role of HCl in the stomach?

Answer: HCl makes the medium acidic, which helps pepsin to function.

4. Which enzyme is present in saliva and what is its function?

Answer: Salivary amylase; it converts starch into sugar.

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Short Answer Questions (2–3 Marks)

5. State the function of the following: (i) Mucus, (ii) Villi

Answer:

(i) Mucus – Protects the inner lining of the stomach from acid.

(ii) Villi – Finger-like projections in the small intestine that absorb digested food into the blood.

6. What changes does food undergo in the stomach?

Answer:

Food mixes with gastric juice.

Pepsin digests proteins.

HCl makes the medium acidic.

Mucus protects the stomach lining.

7. Write the role of bile in digestion.

Answer: Bile emulsifies large fat globules into smaller droplets, making it easier for enzymes to digest fats.

8. Which organs secrete digestive juices into the small intestine? Mention their roles.

Answer:

Liver: Secretes bile for emulsification of fats.

Pancreas: Secretes pancreatic juice containing trypsin, lipase, and amylase.

Intestine: Secretes intestinal juice for final digestion.

1. पेरिस्टैल्टिक मूवमेंट का क्या कार्य है?

उत्तर: पेरिस्टैल्टिक मूवमेंट भोजन को ग्रासनली से पेट तक पहुँचाने का कार्य करता है, जिसमें मांसपेशियों का संकुचन और शिथिलन होता है।

2. गैस्ट्रिक जूस के तीन घटकों के नाम लिखिए।

उत्तर: पेप्सिन, हाइड्रोक्लोरिक एसिड (HCl), और म्यूकस।

3. पेट में HCl की भूमिका क्या है?

उत्तर: HCl माध्यम को अम्लीय बनाता है, जिससे पेप्सिन एंजाइम कार्य कर सके।

4. लार में कौन सा एंजाइम होता है और उसका कार्य क्या है?

उत्तर: लार में सैलिवरी एमाइलेज होता है, जो स्टार्च को शर्करा (शुगर) में बदलता है।

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**लघु उत्तर प्रश्न (2–3 अंक)**

5. निम्नलिखित के कार्य लिखिए: (i) म्यूकस, (ii) विली

उत्तर:

(i) म्यूकस – पेट की भीतरी परत को अम्ल से सुरक्षा प्रदान करता है।

(ii) विली – छोटी आंत में उंगली जैसी संरचनाएँ हैं, जो पचे हुए भोजन को रक्त में अवशोषित करती हैं।

6. पेट में भोजन के साथ क्या परिवर्तन होते हैं?

उत्तर:

- भोजन गैस्ट्रिक जूस के साथ मिल जाता है।

- पेप्सिन प्रोटीन को पचाता है।

- HCl माध्यम को अम्लीय बनाता है।

- म्यूकस पेट की परत की रक्षा करता है।

7. पित्त रस (Bile) का पाचन में क्या कार्य है?

उत्तर: पित्त रस वसा की बड़ी बूँदों को छोटे-छोटे बूँदों में विभाजित (इमल्सिफिकेशन) करता है, जिससे वसा का पाचन आसान हो जाता है।

8. छोटी आंत में कौन-कौन से अंग पाचक रस छोड़ते हैं? उनके कार्य लिखिए।

उत्तर:

- यकृत (लिवर): वसा के इमल्सिफिकेशन के लिए पित्त रस बनाता है।

- अग्न्याशय (पैंक्रियास): ट्रिप्सिन, लाइपेज़ और एमाइलेज युक्त अग्न्याशयी रस बनाता है।

- आंत (इंटेस्टाइन): अंतिम पाचन के लिए आंत्र रस (इंटेस्टाइनल जूस) बनाता है।

4. Write the functions of the large intestine.

Answer:

Absorbs excess water from undigested food.

Removes the remaining waste material through the anus.

5. What are villi? What is their function?

Answer:

Villi are finger-like projections in the small intestine.

They increase surface area to absorb digested food into the bloodstream.

6. Mention the enzymes present in pancreatic juice and their functions.

Answer:

Trypsin: Breaks down proteins into peptones.

Lipase: Breaks down fats into fatty acids and glycerol.

Amylase: Helps in the digestion of carbohydrates.

4. बड़ी आंत के कार्य लिखिए।

उत्तर:

- अपचित भोजन से अतिरिक्त जल को अवशोषित करती है।

- शेष अपशिष्ट पदार्थ को गुदा द्वारा शरीर से बाहर निकालती है।

5. विली क्या हैं? इनका क्या कार्य है?

उत्तर:

विली छोटी आंत में उंगली जैसी आकृति की रचनाएँ हैं।

इनका कार्य पचे हुए भोजन का अवशोषण कर उसे रक्त में पहुँचाना है।

6. अग्न्याशयी रस में कौन-कौन से एंजाइम होते हैं और उनके कार्य क्या हैं?

उत्तर:

- ट्रिप्सिन: प्रोटीन को पेप्टोन में तोड़ता है।

- लाइपेज़: वसा को फैटी एसिड और ग्लिसरॉल में तोड़ता है।

- ऐमाइलेज: कार्बोहाइड्रेट के पाचन में सहायता करता है।

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