Question 1

Why do organisms breathe?

Accepted Answer

Organisms breathe to get energy from food through respiration. Oxygen taken in during breathing breaks down glucose into carbon dioxide, water, and energy, which is essential for various life processes.

Question 2

What is the breakdown of glucose with the use of oxygen called?

Accepted Answer

Aerobic respiration is the breakdown of glucose that takes place in the presence of oxygen, releasing a large amount of energy, carbon dioxide, and water.

Question 3

Which organisms can survive in the absence of air (oxygen) and are used to make wine and beer?

Accepted Answer

Yeasts are single-celled organisms that respire anaerobically in the absence of air. During this process, they yield alcohol and are used in the brewing and baking industries.

Question 4

What accumulates in our muscles during heavy exercise, causing muscle cramps?

Accepted Answer

During heavy exercise, muscle cells respire anaerobically when oxygen supply is insufficient, leading to the partial breakdown of glucose and accumulation of lactic acid, which causes cramps.

Question 5

What relief measure helps in reducing muscle cramps?

Accepted Answer

गर्म पानी से नहाना या मालिश करना रक्त परिसंचरण में सुधार करता है, जिससे मांसपेशी कोशिकाओं को ऑक्सीजन की आपूर्ति बढ़ती है, जिससे लैक्टिक एसिड का कार्बन डाइऑक्साइड और पानी में पूर्ण विघटन संभव होता है।

Respiration in Organisms — CBSE Class 7 Science Important Questions & Revision Notes