Q.60 Given below are two statements:
Statement-I: An organism in which a chromosome, or a piece of a chromosome is over represented is referred to as a hypoploid.
Statement-II: An organism in which a chromosome, or a piece of a chromosome is under represented is referred to as a hyperploid.
In the light of the above statements, choose the correct answer
from the options given below:
(A) Both Statement-I and Statement-II are true
(B) Both Statement-I and Statement-II are false
(C) Statement-I is true but Statement-II is false
(D) Statement-I is false but Statement-II is true
Solution to Question 60: Analyzing Hypoploid and Hyperploid Definitions
Both statements reverse the standard genetic terminology for aneuploidy, making them incorrect. Let’s evaluate each statement and option in detail for clarity, especially for exams like NEET or CSIR NET.
Statement-I: “An organism in which a chromosome, or a piece of a chromosome is over represented is referred to as a hypoploid.”
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Evaluation: This is false.
“Over represented” means extra chromosomes or segments (e.g., trisomy: 2n+1). Hyperploid describes over-representation (gain), while hypoploid means under-representation (loss, e.g., monosomy: 2n-1). Hypoploid organisms have fewer chromosomes/segments than normal.
Statement-II: “An organism in which a chromosome, or a piece of a chromosome is under represented is referred to as a hyperploid.”
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Evaluation: This is false.
“Under represented” means missing chromosomes/segments. Hypoploid fits loss (deficiency), while hyperploid fits gain (excess). These terms fall under aneuploidy (numerical chromosomal imbalance).
Option Analysis
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(A) Both Statement-I and Statement-II are true: Incorrect. Both definitions are swapped.
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(B) Both Statement-I and Statement-II are false: Correct. Matches the evaluations—hypoploid is under-representation, hyperploid is over-representation.
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(C) Statement-I is true but Statement-II is false: Incorrect. Statement-I is false.
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(D) Statement-I is false but Statement-II is true: Incorrect. Both are false.
Final Answer: (B)
Introduction to Hypoploid Hyperploid Chromosome Over Represented Under Represented
In genetics, hypoploid hyperploid chromosome over represented under represented terms describe aneuploidy—imbalances in chromosome number vital for NEET, CSIR NET, or genetics exams. This article clarifies definitions, common errors in MCQs, and examples like Down syndrome (hyperploid), helping students ace questions on chromosomal aberrations.
Core Definitions: Aneuploidy Classification
Aneuploidy involves gain/loss of specific chromosomes from the euploid (normal) set.
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Hyperploid: Chromosome(s) or segment over represented (extra copies, e.g., 2n+1 trisomy, 2n+2 tetrasomy). Causes: Nondisjunction in meiosis/mitosis.
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Hypoploid: Chromosome(s) or segment under represented (missing copies, e.g., 2n-1 monosomy, 2n-2 nullisomy).
| Term | Representation | Example | Condition |
|---|---|---|---|
| Hyperploid | Over (gain) | Trisomy 21 | Down syndrome |
| Hypoploid | Under (loss) | Monosomy X | Turner syndrome |
Causes and Mechanisms
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Origin: Meiotic nondisjunction (chromosomes fail to separate), leading to gametes with extra/missing chromosomes. Fertilization with normal gamete yields aneuploids.
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Hypoploid effects: Often lethal due to gene dosage imbalance (e.g., monosomy rare in animals).
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Hyperploid examples: Viable in plants (e.g., trisomic tomatoes); in humans, trisomy 21 survives.
MCQ Pitfall: Swapped Definitions
Exams test recall—Statement-I wrongly calls over-representation “hypoploid,” and II calls under-representation “hyperploid.” Correct answer: (B) Both false, as prefixes “hypo-” (less) and “hyper-” (more) dictate meanings.
Significance in Genetics and Disease
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Cancer link: Hyperdiploidy (>50 chromosomes) in leukemia predicts good prognosis.
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Plant breeding: Hyperploids used for trait enhancement; hypoploids studied for deficiency effects.
Master hypoploid hyperploid chromosome over represented under represented to avoid traps—practice with diagrams of nondisjunction for visual recall.
