What is the answer to the genetic disorders NEET 2026 statement question?
The genetic disorders NEET 2026 answer is B, both statements are false, because neither syndrome is paired with its correct chromosomal cause. The question tests whether you can distinguish an extra chromosome 21 from a missing X chromosome.
The source is NEET UG 2026, held on 21 June 2026, Code-50, Biology. The question bank classifies it as medium difficulty; that is not an official NTA rating.
In plain language, Statement I links Down’s syndrome to a missing X chromosome. Statement II links Turner’s syndrome to an extra chromosome. Judge each pairing independently, then use these answer combinations:
How do you check both statements using NCERT?
Down’s syndrome involves trisomy 21; Turner’s syndrome involves a missing X chromosome. Those corrected associations make both statements false. The supplied official solution follows NCERT Class 12 Biology, Chapter 5, Principles of Inheritance and Variation. Establish the correct chromosome change before looking at the answer combinations.
Step 1: Write the correct Down’s association. Down’s syndrome is caused by an additional copy of chromosome 21, called trisomy 21. That means three copies of chromosome 21 rather than the usual two. In the standard whole-chromosome case discussed here:
Step 2: Check Statement I. It assigns a missing X chromosome to Down’s syndrome. A missing X describes Turner’s syndrome, so Statement I is false.
Step 3: Write the correct Turner’s association. One X chromosome is absent, giving 45 chromosomes, represented in the supplied NCERT explanation as XO. XO means one X chromosome with the other sex chromosome absent. O marks absence, not another chromosome.
Step 4: Check Statement II. Turner’s involves monosomy, meaning one chromosome from a pair is missing. It does not involve an extra chromosome, so Statement II is false.
The corrected pairings are:
- Down’s: Extra chromosome 21; trisomy.
- Turner’s: Missing X chromosome; monosomy.
Step 5: Map the results to the options. False/false gives B. Each other option requires at least one true statement:
- Reject A because it requires both statements to be true.
- Reject C because it requires Statement I to be true.
- Reject D because it requires Statement II to be true.
How can swapping the causes lead to wrong option A?
Option A results if you accept two valid biological phrases without checking their syndrome names. “Missing chromosome” and “extra chromosome” can both describe causes of chromosomal disorders. That does not make either phrase correct for every disorder.
The faulty method attaches “missing X” to Down’s and “extra chromosome” to Turner’s. With both associations reversed, Statement I appears true and Statement II appears true. The answer mapping then produces A.
The failure is in the pairing, not in recognising the vocabulary. A complete statement must connect the right syndrome to the right chromosome change.
Use this repair routine:
- Identify the syndrome named.
- Retrieve its correct chromosome change.
- Judge that statement as true or false.
- Only then consult the answer combinations.
What does trisomy 21 mean for the chromosome count?
The correct combination is 47 chromosomes in total and three copies of chromosome 21: option C. This is original same-chapter practice 1, not a verified PYQ.
In the standard whole-chromosome trisomy 21 case, which combination gives the total count and copies of chromosome 21?
First, the normal pair gains one copy:
Then calculate the total:
21 identifies the chromosome involved, not the total chromosome count.
What does 45, XO mean in Turner’s syndrome?
It means one X chromosome is present and the other sex chromosome is absent: option B. This is original same-chapter practice 2, not a verified PYQ.
Which interpretation of 45, XO is correct?
The count is:
One X remains present, so absence of one X does not mean absence of all X chromosomes. O marks the missing partner; it is not a separate chromosome.
Which statement about Klinefelter’s and Turner’s syndrome is correct?
Only Statement I below is true, so the answer is C. This is original same-chapter practice 3, not a verified PYQ.
Assess these statements:
- I: Klinefelter’s syndrome has the chromosome complement 47, XXY.
- II: Turner’s syndrome results from an additional X chromosome.
Use the original mapping:
Statement I is true: 47, XXY contains an extra X. Statement II is false: Turner’s is 45, XO, with a missing sex chromosome.
Down’s involves an extra chromosome 21, an autosome. Klinefelter’s involves an extra X, so it is not an autosomal trisomy. Before selecting an option, check which chromosome is involved and whether it is gained or lost.
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Keep going with VSEPR Theory and Bond Angles NEET 2010: Why Option B Is Correct.
Frequently asked questions
What is the answer to the genetic disorders NEET 2026 statement question?
The answer is B: both statements are false. Statement I incorrectly links Down’s syndrome to a missing X chromosome, while Statement II incorrectly links Turner’s syndrome to an extra chromosome.
How many chromosomes are present in Down’s syndrome?
In the standard whole-chromosome trisomy 21 case, there are 47 chromosomes in total. Chromosome 21 has three copies instead of two; 21 identifies the chromosome, not the total count.
What does 45, XO mean in Turner’s syndrome?
It means 45 chromosomes: 44 autosomes and one X chromosome, with the other sex chromosome absent. O marks absence, not a separate chromosome, and one X remains present.
What is the difference between Klinefelter’s and Turner’s syndrome?
Klinefelter’s syndrome has the chromosome complement 47, XXY, with an extra X chromosome. Turner’s syndrome is represented here as 45, XO, with one sex chromosome missing. Check both the chromosome involved and whether it is gained or lost.