![Q.40 Determine the correctness or otherwise of the following Assertion [a] and the Reason [r] Assertion [a]: A typule and its immediate descendant cells are specialized and are called toipotent Reason [C]: Totipotent cells retain the capacity to differentiate into only a few cell types (A) Both [a] and [r] are false (B) Both [a] and [r] are true but [r] is not the correct reason for [a] (C) Both [a] and [r] are true and [r] is the correct reason for [a] (D) [a] is true but is false](https://www.letstalkacademy.com/wp-content/uploads/2026/01/slide_40-10.png)
Q.40 Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]
Assertion [a]: A typule and its immediate descendant cells are specialized and are called toipotent
Reason [C]: Totipotent cells retain the capacity to differentiate into only a few cell types
(A) Both [a] and [r] are false
(B) Both [a] and [r] are true but [r] is not the correct reason for [a]
(C) Both [a] and [r] are true and [r] is the correct reason for [a]
(D) [a] is true but is false
Correct Answer: (A) Both [a] and [r] are false
The assertion incorrectly describes totipotent cells as “specialized,” while the reason wrongly limits their differentiation potential.
Assertion Analysis
Assertion [a] states that a zygote (likely intended instead of “typu le,” a probable typo) and its immediate descendant cells are specialized and called totipotent. Totipotent cells, such as zygotes, are actually unspecialized with maximum developmental potential to form all cell types including extraembryonic tissues. This makes [a] false.
Reason Analysis
Reason [r] claims totipotent cells differentiate into only a few cell types. Totipotency means capacity for all cell types in an organism plus extraembryonic structures, contrasting with multipotent (few types) or pluripotent (many embryonic types) cells. Thus [r] is false.
Option Breakdown
| Option | Correctness | Explanation |
|---|---|---|
| (A) Both [a] and [r] are false | Correct | Matches analysis: [a] wrong on specialization; [r] wrong on differentiation scope |
| (B) Both true, [r] not reason for [a] | Incorrect | Both statements false |
| (C) Both true, [r] correct reason | Incorrect | Both false; unrelated anyway |
| (D) [a] true, [r] false | Incorrect | [a] false |
Totipotent cells represent the pinnacle of cellular potency, vital for exams like IIT JAM Biotechnology. This article dissects Q40’s totipotent cells assertion reason question, clarifying misconceptions for competitive exam success.
Understanding Totipotency
Totipotent cells like zygotes divide to produce every cell type in an organism, including placenta—far from “specialized.” Early blastomeres retain this capacity briefly before potency restricts.
Question Dissection
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Assertion [a] Error: Claims zygote/descendants “specialized”—opposite of reality.
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Reason [r] Error: Limits to “few cell types”—totipotency means complete potential.
Exam Strategy Tip
Such assertion-reason questions test core definitions. Recall: totipotent > pluripotent > multipotent > unipotent in potency hierarchy.
