Life Processes in Animals Class 7 MCQ
hardLife Processes in Animals Class 7 MCQ
Life Processes in Animals Class 7 MCQ
Question 1.
What is the primary function of the alimentary canal in humans?
(a) To transport oxygen
(b) To break down food
(c) To circulate blood
(d) To filter waste
Answer:
(b) To break down food
Question 2.
Which part of the digestive system is responsible for mechanical digestion?
(a) Stomach
(b) Mouth
(c) Small intestine
(d) Large intestine
Answer:
(b) Mouth
Question 3.
What do fish use for breathing?
(a) Lungs
(b) Skin
(c) Gills
(d) Fins
Answer:
(c) Gills
Question 4.
Which of the following is NOT a life process?
(a) Nutrition
(b) Respiration
(c) Communication
(d) Excretion
Answer:
(c) Communication
Question 5.
In which part of the respiratory system does gas exchange occur?
(a) Trachea
(b) Bronchi
(c) Alveoli
(d) Larynx
Answer:
(c) Alveoli
Question 6.
Which animal uses its skin for gas exchange?
(a) Fish
(b) Frog
(c) Bird
(d) Cow
Answer:
(b) Frog
Question 7.
What is the function of the diaphragm in the respiratory system?
(a) To filter air
(b) To help in the movement of lungs
(c) To produce sound
(d) To transport oxygen
Answer:
(b) To help in the movement of lungs.
Case Study
I. Role of saliva in digestion
Saliva plays a vital role in the initial stages of digestion. It contains enzymes that break down starches into simpler sugars. When we chew food, saliva mixes with it, enhancing the taste and aiding digestion. For example, chewing chapati or rice releases sweetness due to the breakdown of starch. This process illustrates how digestion begins even before food reaches the stomach.
Question 1.
What is the main function of saliva in the initial stage of digestion?
(a) To absorb nutrients
(b) To break down starches into simpler sugars
(c) To kill bacteria
(d) To transport food to the stomach
Answer:
(b) To break down starches into simpler sugars
Explanation: Saliva contains enzymes, such as salivary amylase, which help break down starch (a complex carbohydrate) into simpler sugars right in the mouth.
Question 2.
Why does chapati or rice taste sweet after being chewed for some time?
(a) Because of the spices added
(b) Because saliva turns starch into sugar
(c) Because of the presence of proteins
(d) Because of the temperature of the food
Answer:
(b) Because saliva turns starch into sugar
Explanation: The enzyme in saliva breaks down the starch present in chapati or rice into simpler sugars, which taste sweet.
Question 3.
Saliva contains ............ that help break down starches into simpler sugars.
Answer:
enzymes
Question 4.
The process of digestion begins in the ............ when saliva mixes with food.
Answer:
mouth
Question 5.
Digestion only starts after food reaches the stomach. (True/False)
Answer:
False
Explanation: Digestion begins in the mouth, where saliva starts breaking down starches into sugars even before the food reaches the stomach.
II. The process of respiration
Respiration is a chemical process that converts glucose into usable energy, using oxygen. This process occurs in the cells and produces carbon dioxide and water as byproducts. Breathing, which involves inhalation and exhalation, is a physical process that facilitates the exchange of gases in the lungs. Understanding respiration helps us recognize the importance of oxygen for sustaining life.
Question 1.
What is the main function of respiration in cells?
Answer:
To convert glucose into usable energy.
Question 2.
Name the two byproducts of respiration.
Answer:
Carbon dioxide and water.
Question 3.
Differentiate between breathing and respiration.
Answer:
Breathing is a physical process involving inhalation and exhalation to exchange gases in the lungs. Respiration is a chemical process that occurs in cells, using oxygen to break down the food (glucose) and release energy.