Q10
1 markMCQSection A

In human respiratory system, when a person breathes in, the position of ribs and diaphragm will be :

Life Processes
Respiration in Human Beings

Options

(A)lifted ribs and curve/dome shaped diaphragm.
(B)lifted ribs and flattened diaphragm.
(C)relaxed ribs and flattened diaphragm.
(D)relaxed ribs and curve/dome shaped diaphragm.
Official Answer

The correct option is B: lifted ribs and flattened diaphragm.

lifted ribsflattened diaphragminhalationthoracic cavity

Marking Scheme

  • 1Identification of rib movement (lifted ribs) during inhalation (0.5 marks)
  • 2Identification of diaphragm shape (flattened) during inhalation (0.5 marks)

Hint

Think about how you expand your chest to pull air in. The diaphragm must move down (flatten) to create more space.

Quick Oral Answer

During inhalation, the ribs are lifted up and the diaphragm is flattened to increase the volume of the chest cavity, drawing air into the lungs.

Analysis & Explanation

During inhalation (breathing in), the body actively expands the thoracic cavity to draw air into the lungs:

  1. Ribs: The intercostal muscles contract, causing the ribs to move upward and outward (lifted ribs).
  2. Diaphragm: The diaphragm muscle contracts and moves downward, changing from its relaxed dome shape to a flattened shape.

This combined movement increases the volume of the chest cavity, lowering the air pressure inside the lungs relative to the atmospheric pressure, which forces outside air to rush into the lungs. Therefore, Option B is correct, while options involving relaxed ribs or a dome-shaped diaphragm during inhalation are incorrect.

Common Mistakes

  1. 1Confusing inhalation with exhalation, where the diaphragm relaxes and returns to its dome shape.

Interesting Facts

The surface area of human lungs is roughly equivalent to the size of a tennis court, optimized for efficient gas exchange!

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2024?

This question carries 1 mark in the CBSE Class 10 Science 2024 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Life Processes" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Respiration in Human Beings" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2024 paper?

This is a MCQ question from Section A in the CBSE Class 10 Science 2024 paper.