If you are looking for DAV Class 4 Science Chapter 1 Question Answer My Body of My Living World science book, then you are at the right place. Here at NCERTBooksPDF, Class 4 Science Chapter 1 exercises are solved with accurate, child-friendly explanations and complete solutions to help DAV students score top marks in their exams.
Table of Contents
- DAV Class 4 Science Chapter 1 My Body Solutions
- A. Fill in the Blanks
- B. Match the Following
- C. Tick the Correct Option
- D. Answer the Following Questions in Brief
- E. Answer the Following Questions (With Foodpath)
- Value-Based Questions
- Something to Do
DAV Class 4 Science Chapter 1 My Body Solutions
DAV Class 4 Science Chapter 1 My Body covers human internal organs, teeth types, digestion, and healthy eating habits. Below are the complete step-by-step solutions for all textbook exercises.
A. Fill in the blanks.
1. The body organs that cannot be seen from outside are called internal organs.
2. Flat teeth are in the front of the mouth.
3. Tongue is used for tasting and speaking.
4. Saliva is secreted by salivary glands.
5. Flies can transfer germs to uncovered food.
Answer: (1) internal | (2) front | (3) tasting, speaking | (4) salivary glands | (5) germs
B. Match the following:
| Organ / Teeth | Function / Count | Correct Match |
|---|---|---|
| 1. Milk teeth | (a) Absorption of water | (e) Twenty |
| 2. Large intestine | (b) Absorption of digested food | (a) Absorption of water |
| 3. Permanent teeth | (c) Undigested waste is collected | (d) Thirty-two |
| 4. Rectum | (d) Thirty-two | (c) Undigested waste is collected |
| 5. Small intestine | (e) Twenty | (b) Absorption of digested food |
Answer: (1) e, (2) a, (3) d, (4) c, (5) b
C. Tick (✓) the correct option.
1. The teeth, used to tear food into pieces, are known as—
(a) incisors
(b) canines
(c) molars
(d) premolars
Answer: (b) canines
Explanation: Canines are the sharp pointed teeth located on either side of the front flat teeth (incisors), used specifically for tearing food.
2. Ria’s mother is thirty-two years old. She is likely to have—
(a) 20 permanent teeth
(b) 20 temporary teeth
(c) 32 permanent teeth
(d) 32 temporary teeth
Answer: (c) 32 permanent teeth
Explanation: An adult human has a complete set of 32 permanent teeth (16 in the upper jaw and 16 in the lower jaw).
3. The organ, which secretes digestive juices in the small intestine, is the—
(a) liver
(b) salivary glands
(c) stomach
(d) food pipe
Answer: (a) liver
Explanation: The liver (along with the pancreas) produces digestive juices and pours them into the small intestine to complete digestion.
4. The food gets completely digested in the—
(a) mouth
(b) stomach
(c) small intestine
(d) large intestine
Answer: (c) small intestine
Explanation: In the small intestine, food mixes with digestive juices from the liver and pancreas and gets completely digested and absorbed into the bloodstream.
5. An eight-year-old child is likely to have—
(a) only temporary teeth
(b) only permanent teeth
(c) both temporary and permanent teeth
(d) no teeth at all
Answer: (c) both temporary and permanent teeth
Explanation: Between 6 and 12 years of age, milk teeth begin to fall out and new permanent teeth erupt in their place. Therefore, an 8-year-old child has a mixed set of both temporary and permanent teeth.
D. Answer the following questions in brief.
1. Name the organ through which food enters the stomach.
Answer: Food enters the stomach through the food pipe (Oesophagus).
2. How many sets of teeth are formed during one’s life time? Name them.
Answer: Two sets of teeth are formed during a person’s lifetime:
- Milk teeth (Temporary teeth): 20 in number, appearing during early childhood.
- Permanent teeth: 32 in number, replacing milk teeth from age six onwards.
3. Write any one difference between milk teeth and permanent teeth.
Answer: Milk teeth are temporary and 20 in number, whereas permanent teeth are 32 in number and remain throughout adult life if properly protected.
4. What do you mean by the term ‘digestion’?
Answer: The process of breaking down complex food materials into simpler, soluble forms that can be easily absorbed and used by the body is called digestion.
5. What happens to the food when it enters the stomach?
Answer: When food enters the stomach, it mixes thoroughly with digestive juices secreted by the stomach walls and becomes partially digested.
E. Answer the following questions.
1. List five good habits that should be taken care of at the time of eating food.
Answer: Five good eating habits are:
- Wash hands thoroughly with soap and clean water before eating.
- Chew food properly before swallowing, and do not speak while chewing.
- Eat meals at fixed regular intervals in a calm and clean place.
- Include green vegetables, fresh seasonal fruits, and whole grains in daily meals.
- Drink 8 to 10 glasses of clean water every day and avoid overeating junk food.
2. Name the different types of teeth present in the mouth. Also mention their functions.
Answer: Human jaws have four distinct types of teeth:
| Type of Teeth | Total Count | Primary Function |
|---|---|---|
| 1. Incisors (Flat teeth) | 8 (4 upper, 4 lower) | Used for biting and cutting food into pieces. |
| 2. Canines (Pointed teeth) | 4 (2 upper, 2 lower) | Used for tearing tough food materials. |
| 3. Premolars (Broad & grooved) | 8 (4 upper, 4 lower) | Used for chewing and grinding food. |
| 4. Molars (Broad & grooved) | 12 (6 upper, 6 lower) | Used for fine crushing and grinding food before swallowing. |
3. Why is it important to chew the food properly?
Answer: Chewing food properly breaks large food morsels into small bits and mixes them thoroughly with saliva. Saliva softens food and converts insoluble starch into soluble sugar, making swallowing easy and ensuring smooth digestion in the stomach and intestines.
4. Why is washing of fruits and vegetables important for us?
Answer: Unwashed fruits and vegetables often carry dust, harmful chemical pesticides, germs of diseases, and microscopic worm eggs. If eaten raw without washing, these germs enter our digestive system and can cause serious illnesses like diarrhea, vomiting, food poisoning, and stomach worms.
5. Sheena’s mother often tells her not to eat too many sweets and chocolates. Why do you think she says so?
Answer: Sweets and chocolates contain high amounts of sugar that stick to teeth. Bacteria present in the mouth feed on this sugar and produce harmful acids. These acids attack the tooth enamel, causing cavities, tooth decay, toothache, and bad breath.
6. Complete the given foodpath:
Answer:
Mouth ➔ Food Pipe (Oesophagus) ➔ Stomach ➔ Small Intestine ➔ Large Intestine ➔ Rectum ➔ Anus
- Mouth: Food is chewed by teeth, moistened by saliva, and pushed down.
- Food Pipe: Pushes food down into the stomach.
- Stomach: Churns food with gastric juices for partial digestion.
- Small Intestine: Completely digests food and absorbs nutrients into blood.
- Large Intestine: Absorbs water from undigested food waste.
- Rectum: Temporarily stores semi-solid waste.
- Anus: Expels undigested waste out of the body.
Value-Based Questions
It was lunch time in the school. Rahul and his friends gathered to have lunch together. Rahul did not find his lunch box in his bag. His friend Sanyam immediately offered to share his lunch with him. Rahul, however, moved out of the class and bought food from the roadside vendor outside the school gate.
1. What would you do if you were in Rahul’s place?
Answer: If I were in Rahul’s place, I would happily and gratefully accept my friend Sanyam’s offer to share his home-cooked food, rather than risking my health by eating unhygienic food from a roadside vendor.
2. Sanyam tried to share his food with Rahul. In what situations do you share/help your friends?
Answer: I share my stationery (pencils, erasers), storybooks, and tiffin when my friends forget theirs at home. I also help my classmates understand difficult school topics and cheer them up when they feel low.
3. Do you think that eating food from roadside vendors is a healthy option?
Answer: No, eating food from roadside vendors is not healthy. Roadside food is exposed to dust, vehicular smoke, and flies, and is often prepared with unclean water and hands, which can easily cause infections like typhoid, cholera, and diarrhea.
Something to Do
1. Denture Making Activity: Take playing clay and roll it into the shape of upper and lower jaws. Place peeled peanuts shaped like incisors (flat), canines (pointed), and molars (broad with grooves) to observe how teeth fit inside human gums.
Related Chapters:
- DAV Class 4 Science Solutions (All Chapters)
- DAV Class 4 Science Chapter 2 Plants
- DAV Class 4 Science Chapter 3 Flowers and Fruits
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