Question 191 markMCQSection A

$Assertion (A) : The inner walls of the small intestine have finger like projections called villi which are rich in blood. Reason (R) : These villi have a large surface area to help the small intestine in completing the digestion of food.$

Q: Assertion (A) : The inner walls of the small intestine have finger like projections called villi which are rich in blood. Reason (R) : These villi have a large surface area to help the small intestine in completing the digestion of food.

The correct option is (c). Assertion (A) is true because the inner lining of the small intestine has numerous finger-like projections called villi which are richly supplied with blood vessels. However, Reason (R) is false because the primary function of the large surface area provided by the villi is to facilitate the absorption of digested food, not to complete the digestion of food.

Life Processes

Nutrition in Human Beings

Options

(a)

Both (A) and (R) are true and (R) is the correct explanation of (A).

(b)

Both (A) and (R) are true but (R) is not the correct explanation of (A).

(c)

(A) is true but (R) is false.

(d)

(A) is false but (R) is true.

Official answer

The correct option is (c). Assertion (A) is true because the inner lining of the small intestine has numerous finger-like projections called villi which are richly supplied with blood vessels. However, Reason (R) is false because the primary function of the large surface area provided by the villi is to facilitate the absorption of digested food, not to complete the digestion of food.

villi

absorption

surface area

blood vessels

digestion

Marking scheme

1. ${"points": 1.0, "description": "Correctly identifying that Assertion (A) is true but Reason (R) is false."}$

Hint

$Consider whether the primary role of the villi's large surface area is chemical digestion or physical absorption.$

Quick oral answer

$Villi do not digest food; they increase the surface area of the inner lining of the small intestine so that digested nutrients can be rapidly absorbed into the bloodstream.$

Common mistakes

1. $Students often confuse absorption with digestion, assuming that because villi are in the small intestine (where digestion is completed), they must help in digestion rather than absorption.$

Analysis and explanation

Assertion (A) is true: The inner walls of the small intestine contain villi, which are richly supplied with blood vessels to carry absorbed food to all cells of the body. Reason (R) is false: The villi increase the surface area specifically for the absorption of digested food, whereas the completion of digestion occurs due to various enzymes present in the intestinal juice, pancreatic juice, and bile in the lumen of the small intestine. Therefore, (A) is true but (R) is false.

Interesting facts

$The total surface area of the human small intestine is greatly expanded by villi and microvilli, making it roughly equivalent to the size of a tennis court to maximize nutrient absorption!$

Question details

Q19 of 39 questions

Board: CBSE
Class: Class 10
Subject: Science
Year: 2023
Section: Section A
Marks: 1
Type: MCQ
Chapter: Life Processes
Topic: $Nutrition in Human Beings$
Bloom's level: Understanding
Syllabus topic: $Human Alimentary Canal: Structure and function of small intestine$

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Frequently asked questions

$How many marks does this question carry in CBSE Class 10 Science 2023?$

$This question carries 1 mark in the CBSE Class 10 Science 2023 examination.$

$Which chapter does this question come from in Science?$

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

$What topic does this question cover in Science?$

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

$What type of question is this in the CBSE Class 10 Science 2023 paper?$

$This is a MCQ question from Section A in the CBSE Class 10 Science 2023 paper.$