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Human Body A Wonder Digestion and Respiration Class 7 Questions and Answers Notes
Class 7 Basic Science Chapter 5 Human Body A Wonder Digestion and Respiration Question Answer Pdf
Basic Science Class 7 Chapter 5 Question Answer Kerala Syllabus
Let Us Assess
Question 1.
Which of the following combination is correct?
a. Goat, Horse, Crow, Pigeon (Herbivores)
b. Leopard, Vulture, Elephant, Lizard (Carnivores)
c. Man, Hen, Monkey, Peacock (Omnivores)
Answer:
c. Man, Hen, Monkey, Peacock
Question 2.
In which of the following organ,digestion is completed?
a. Mouth b. Small intestine c. Large intestine d. Stomach
Answer:
Small intestine
Question 3.
What are the precautionary steps to be taken to prevent tooth decay?
Answer:
- Wash mouth properly after having food
- Brush teeth in the morning, before breakfast and at night, after dinner
- Clean mouth well after consuming sweets
Question 4.
Compare the dentition of a six year old child and that of an adult.
Answer:
In infants, teeth development starts around the age of six months. These teeth are known as milk teeth. Ten milk teeth each develop at the upper and lower jaws (total – 20). Permanent teeth are those that replace milk teeth when they fall off. If the permanent teeth break or fall off, new teeth will not grow in its place. There will be 32 permanent teeth in an adult person.
Question 5.
A person is lying down and eating food. Do you think the food will reach the stomach? Why?
Answer:
Yes, the food will reach the stomach. This is due to peristalsis. The wave-like movement of the oesophageal wall helps food to reach the stomach. This movement is called peristalsis.
Class 7 Basic Science Chapter 5 Extended Activities Answers
Question 1.
Like man, other organisms also breathe. Observe the body movements of cat, cow etc during inhalation and exhalation.
Answer:
Hint:
Watch their chests and abdomens. As they inhale, their chests and bellies expand to take in air. When they exhale, the chest and belly contract to push air out.
Question 2.
Breathe into a mirror. What do you see? What is the reason?
Answer:
The surface of the mirror fades up. The exhaled air contains moisture. This moisture condenses on the reflecting surface of the mirror.
Question 3.
List out the ideas to be covered in the seminar to be organized in the school on the topic, “Respiratory System and Health” and display them on the bulletin board.
Answer:
Hints:
- Discover how oxygen gets in and carbon dioxide gets out. .
- Explore healthy habits for strong lungs, like exercise and good air quality.
- Learn about common respiratory illnesses and how to prevent them.
Question 4.
Have you ever noticed air pump in the aquarium? Find out its significance.
Answer:
Fishes breath the air dissolved in water. The water in the tanks may run out due to continuous consumption. So, in order to keep the water level steady, sir pumps are used in aquariums.
Class 7 Basic Science Chapter 5 Intext Question and Answers
Question 1.
Compile a list of the organisms you have observed, and their respective food. Present it in the class room.
Answer:
Question 2.
Classify the following living organisms into herbivore, carnivore and omnivore. Write it in the Science Diary.
• Cow
• Goat
• Cat
• Bear
• Rabbit
• Human
• Snakes
• Elephant
• Lion
• Tiger
• Crow
• Wolf
Answer:
| Herbivore | Carnivore | Omnivore |
| Cow | Tiger | Human |
| Goat | Wolf | Crow |
| Rabbit | Lion | Cat |
| Elephant | Snake | Bear |
Question 3.
What are the changes that occur to food in the mouth?
Answer:
- It mixes with saliva
- It gets cut into pieces
- It gets chewed
- It gets masticated
Question 4.
Find out the distinctive features of teeth in carnivorous and herbivorous animals and understand how closely the shape of the teeth is related to their food habits.
Answer:
The canines of carnivores are much developed and it helps in biting and tearing meat. Incisors in herbivores help to bite and tear food, and, premolars and molars to masticate the food.
Question 5.
What are the functions of the tongue?
Answer:
- The taste buds on the tongue, helps us to sense taste.
- Helps in swallowing
- Tongue helps to remove things trapped between teeth
Question 6.
From where does saliva is produced?
Answer:
In salivary glands
Question 7.
To which part of the digestive system does food first reach from the mouth?
Answer:
To Oesophagus
Question 8.
What is oesophagus?
Answer:
The oesophagus is a long tube, that connects the mouth to the stomach. It is made of muscles.
Question 9.
How do the nutrients in the digested food get absorbed into the blood?
Answer:
Villi are the small finger-like projections present in the wall of small intestine. Nutrients in the digested food are absorbed into the blood through the villi.
Question 10.
Complete the flow chart showing the various stages of nutrition.
Answer:
Question 11.
Observe the diagrammatic representation of human digestive system. Write in your Science Diary the names and functions of the labelled parts.
Answer:
| Part | Function |
| A – Salivary gland | Production of saliva |
| B – Oesophagus | Passes food from the mouth to the stomach |
| C – Stomach | Partial digestion of food |
| D – Small intestine | Absorption of nutrients |
| E – Large intestine | Absorption of water and salts |
| F – Rectum | Storage of digestive waste |
Question 12.
Analyze the picture and record in the Science Diary the various stages of nutrition in amoeba.
Answer:
- Fig 1- Approaches food material
- Fig 2-Surrounds the food material and consume it.
- Fig 3-Digest the food material
- Fig 4-Absorbs the nutrients from the digested food.
- Fig 5-Assimilate the digested food
- Fig 6-Egestion of digestive waste.
Question 13.
Observe the pictures of the digestive system of some animals. Do the digestive system of these animals have any similarity with our digestive system? Discuss.
Answer:
Yes, Like the digestive system of human beings, these animals have mouth, oesophagus, stomuch, small intestine, large intestine, return etc.
Question 14.
What happens to the diaphragm during inhalation and exhalation?
Answer:
During inhalation, the diaphragm contracts and flattens. During exhalation, the diaphragm relaxes and both the diaphragm and the lungs returns to their previous positions.
Question 15.
When does the thoracic cavity increase in volume during inhalation or exhalation?
Answer:
During inhalation.
Question 16.
Complete the flowchart of the respiratory tract using the indicators.
Answer:
Question 17.
Observe the table showing the levels of various components in the inhaled and exhaled air.
a) Is the level of all components in inhaled and exhaled air the same? Which all components show difference in percentage?
Answer:
The level of all components in inhaled and exhaled air are not same.
Components that shows difference are – Oxygen, Carbon dioxide, Moisture
b) Which of the components are in higher level and lower level in exhaled air than in inhaled air?
Answer:
In higher level – Carbon dioxide, Moisture
In lower level – Oxygen
c) Which gas is utilized by us in respiration?
Answer:
Oxygen
Question 18.
Which gas do plants take in during respiration?
Answer:
Oxygen
Question 19.
Name the gas released by plants during respiration?
Answer:
Carbon dioxide
Question 20.
Where does the gas exchange take place in plants?
Answer:
In stomata, fine pores found in leaves and tender stem.
Human Body A Wonder Digestion and Respiration Class 7 Notes Extra Questions and Answers
Question 1.
What is nutrition?
Answer:
Nutrition is the process by which organisms obtain and utilize food.
Question 2.
What is the first stage of nutrition?
Answer:
Ingestion
Question 3.
Which is the outermost layer of the teeth?
Answer:
Enamel
Question 4.
What is peristalsis?
Answer:
The wave-like movement of the wall of the oesophagus , helps food to reach the stomach. This movement is called peristalsis.
Question 5.
What are thoracic cavity, Abdominal cavity, and diaphragm?
Answer:
Human lungs are placed in a space inside the chest called thoracic cavity. The cavity below the thoracic cavity is the abdominal cavity. Diaphragm is the muscular wall that separates the thoracic and abdominal cavity.
Question 6.
What is respiratory tract?
Answer:
Air entering through the nostrils reaches alveoli of the lungs. Respiratory tract is this air passage from nostrils to lungs.
Question 7.
In those given below, find out which one is different from others.
a) Goat, elephant, lion, rabbit
b) Vulture, crow, hen, peacock
c) Lion, tiger, deer, wolf
Answer:
a) Lion – Lion is carnivore, others are herbivores
b) Vulture – Vulture is carnivore, others are omnivore
c) Deer – Deer is herbivore, others are carnivore ,
Question 8.
Identify the relation and fill up the blank.
a) Infants: Milk teeth
Adults: …………..
b) Pancreas: Pancreatic juice
Liver: …………..
Answer:
a) Permanent teeth
b) Bile
Question 9.
How does the digestive waste is removed from the body?
Answer:
After the absorption of nutrients, the residues in the digested food move to the large intestine. Water and some salts are absorbed into the large intestine from the digestive waste as needed by the body. Later, the digestive waste stored in the rectum is removed through anus. This process of digestive waste removal from our body is called egestion.
Question 10.
Which is the hardest substance in the human body?
Answer:
Enamel
Question 11.
What is inhalation and exhalation?
Answer:
Inhalation is the process of taking air into the lungs. Exhalation is the process of movement of air from lungs to outside.
Question 12.
Find out how gas exchange takes place in a protozoan like paramecium?
Answer:
Paramecium takes in oxygen dissolved in the surrounding water through the cell membrane and gives out carbon dioxide,
Question 13.
Define Respiration.
Answer:
The process through which organisms receive oxygen from their environment and eliminate carbon dioxide is called respiration.
Human Body A Wonder Digestion and Respiration Class 7 Notes
- Nutrition is the process by which organisms obtain and utilize food.
- The first stage is ingestion.
- Digestion is the second stage of nutrition.
- Nutrients in the digested food are absorbed into the blood through the villi. This is the third stage in nutrition and the process is called absorption.
- The nutrients that reached the blood become part of the body. This is the fourth stage of nutrition and this process is called assimilation.
- The process of digestive waste removal from our body is called egestion. This is the fifth stage of nutrition.
- The process through which organisms receive oxygen from their environment and eliminate carbon dioxide is called respiration.