20 Important Words (Meanings in Hindi)

• Ingestion — भोजन को मुँह में लेना
• Digestion — भोजन को सरल रूप में तोड़ना
• Absorption — सरल पोषक तत्वों का रक्त में सोखना
• Assimilation — पोषक तत्वों का शरीर द्वारा उपयोग
• Egestion — अवशिष्ट पदार्थ को बाहर निकालना
• Buccal Cavity — मुख गुहा
• Oesophagus — आहार नली
• Stomach — अमाशय
• Small Intestine — छोटी आँत
• Large Intestine — बड़ी आँत
• Villi — छोटी आँत की उंगली जैसी संरचनाएँ
• Saliva — लार
• Ruminants — जुगाली करने वाले जानवर
• Rumination — खाए गए भोजन को दुबारा चबाना
• Rumen — पेट का विशेष भाग जहाँ घास पचती है
• Caecum — आँत का थैलीनुमा भाग
• Pseudopodia — झूठे पैर (अमीबा की संरचना)
• Food vacuole — भोजन संग्रह की थैली (अमीबा)
• Bile — यकृत द्वारा निर्मित रस, वसा पचाने में सहायक
• Hydrochloric Acid — अम्ल जो पेट में जीवाणु मारता है और पाचन में मदद करता है

Important Notes

• Animals depend on plants directly or indirectly for food.
• Animal nutrition involves ingestion, digestion, absorption, assimilation, and egestion.
• The human digestive system has: buccal cavity, oesophagus, stomach, small intestine, large intestine, anus, with glands (salivary, liver, pancreas).
• Teeth: incisors (cutting), canines (tearing), premolars & molars (chewing & grinding).
• Saliva breaks down starch to sugar.
• Stomach secretes HCl, mucus, and digestive juices; proteins digest here.
• Liver produces bile (stored in gall bladder) for fat digestion.
• Pancreatic juice digests carbohydrates, proteins, fats.
• Small intestine completes digestion; villi absorb nutrients into blood.
• Large intestine absorbs water and salts; faeces are expelled through anus.
• Ruminants (cows, buffaloes) chew cud in rumination; bacteria in rumen digest cellulose.
• Humans cannot digest cellulose.
• Amoeba engulfs food using pseudopodia into food vacuole; digestion occurs by enzymes.

20 One-Word Answer Questions

1. Process of taking food in body?
   Ingestion.
2. Breaking food into simple form?
   Digestion.
3. Finger-like structures in small intestine?
   Villi.
4. Largest gland in human body?
   Liver.
5. Juice stored in gall bladder?
   Bile.
6. Acid secreted in stomach?
   Hydrochloric acid.
7. Animals chewing cud?
   Ruminants.
8. Cell organelle in amoeba for digestion?
   Food vacuole.
9. False feet of amoeba?
   Pseudopodia.
10. Juice secreted by pancreas?
    Pancreatic juice.
11. Where does protein digestion begin?
    Stomach.
12. Where does fat digestion begin?
    Small intestine.
13. End part of alimentary canal?
    Anus.
14. Milk teeth are replaced by?
    Permanent teeth.
15. Disease caused by tooth bacteria?
    Tooth decay.
16. Where is cellulose digested in ruminants?
    Rumen.
17. Process of removing waste?
    Egestion.
18. Tiny blood vessels in villi?
    Capillaries.
19. Glucose breaks down into?
    CO$_2$, water, energy.
20. Organ producing bile?
    Liver.

20 Very Short Answer Type (1–2 lines)

1. What are the steps of nutrition?
   Ingestion, digestion, absorption, assimilation, egestion.
2. What is peristalsis?
   Wavelike muscular movement pushing food down oesophagus.
3. Role of HCl in stomach?
   Kills bacteria, makes acidic medium.
4. Which juice digests starch?
   Saliva.
5. Which nutrient digestion starts in mouth?
   Carbohydrates (starch).
6. Which nutrient digestion starts in stomach?
   Proteins.
7. Which nutrient digestion completes in small intestine?
   Carbohydrates, proteins, fats.
8. Function of villi?
   Increase surface for absorption of digested food.
9. What is assimilation?
   Using absorbed food for growth/energy.
10. Where is water absorbed?
    Large intestine.
11. What is cud?
    Partially digested food chewed again by ruminants.
12. What is rumination?
    Process of chewing cud.
13. Why can’t humans digest cellulose?
    We lack cellulose-digesting bacteria.
14. What is ORS?
    Oral Rehydration Solution of salt, sugar, water for diarrhoea.
15. What is tooth decay?
    Damage of teeth due to acid produced by bacteria on sugar.
16. Function of bile?
    Breaks down fats into small droplets.
17. What is egestion?
    Removal of undigested waste.
18. Which organ in amoeba digests food?
    Food vacuole.
19. What are pseudopodia?
    False feet for movement and capturing food in amoeba.
20. Where is pancreatic juice secreted?
    Into small intestine.

20 Short Answer Type Questions (2–3 lines)

1. Explain the role of tongue in digestion.
   Tongue mixes saliva with food, helps in swallowing, and has taste buds.
2. Differentiate between milk teeth and permanent teeth.
   Milk teeth: first set, fall by 6–8 years. Permanent teeth replace them, last for life.
3. How is food prevented from entering windpipe?
   By epiglottis, a flap-like valve that closes windpipe while swallowing.
4. What happens in oesophagus?
   Food pushed down by peristaltic movement to stomach.
5. Role of stomach in digestion?
   Secretes acid and juices to digest proteins, churns food.
6. How does liver help in digestion?
   Secretes bile which emulsifies fats for digestion.
7. Role of pancreas in digestion?
   Secretes pancreatic juice that digests carbohydrates, fats, proteins.
8. Why is small intestine very long?
   Provides large area for digestion and absorption of food.
9. What is assimilation?
   Absorbed nutrients used for growth, repair, energy in body cells.
10. Function of large intestine?
    Absorbs water and salts, stores undigested waste as faeces.
11. What is rumination?
    Chewing of cud in ruminants like cows, helps digest cellulose.
12. Why can ruminants digest cellulose?
    Bacteria in rumen digest cellulose into simpler sugars.
13. How does amoeba feed?
    Engulfs food with pseudopodia forming food vacuole, digests inside.
14. What is diarrhoea? How treated?
    Frequent watery stools, treated by giving ORS to prevent dehydration.
15. Explain tooth decay.
    Sugars converted by bacteria to acids damaging enamel, causes cavities.
16. Why do we get instant energy from glucose?
    Glucose directly absorbed into blood and oxidised to release energy quickly.
17. Mention functions of villi.
    Increase surface area, absorb digested nutrients into blood.
18. Name digestive glands in human body.
    Salivary glands, liver, pancreas, stomach and intestinal glands.
19. Difference between ingestion and egestion.
    Ingestion: taking food. Egestion: removal of undigested waste.
20. Why can’t humans survive only on grass?
    Humans lack cellulose-digesting bacteria, cannot digest cellulose of grass.

Important Equations & Processes

Starch + Saliva → Maltose (sugar)

Proteins → (Stomach enzymes) → Peptides → Amino acids

Fats → (Bile + Pancreatic enzymes) → Fatty acids + Glycerol

Glucose + O$_2$ → CO$_2$ + H$_2$O + Energy