Q.69 Match List I with List II :
| List I | List II |
|---|---|
| (A) Duchenne muscular dystrophy | (I) Short stature resulted by addition of chromosome 21 |
| (B) Down syndrome | (II) Deletion in chromosome 5 resulted in small head |
| (C) Chronic myelogenous leukemia | (III) Loss of coordination due to the absence of gene on X-chromosome |
| (D) Cri du chat | (IV) Exchange of a large portion of chromosome 22 with a small fragment from a tip of chromosome 9 |
Choose the correct answer from the options given below :
- (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
- (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
- (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
- (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
Duchenne muscular dystrophy links to X-chromosome gene absence causing muscle weakness, while Down syndrome involves an extra chromosome 21 leading to short stature. The correct matching for this genetics question is option (B): (A)-(III), (B)-(I), (C)-(IV), (D)-(II).
Matching Explanation
Each disorder pairs with its specific genetic cause as follows.
-
(A) Duchenne muscular dystrophy matches (III) Loss of coordination due to absence of gene on X-chromosome. This X-linked recessive disorder results from mutations in the dystrophin gene on Xp21, leading to progressive muscle degeneration and loss of coordination.
-
(B) Down syndrome matches (I) Short stature resulted by addition of chromosome 21. Trisomy 21 (extra chromosome 21) causes characteristic short stature, intellectual disability, and facial features.
-
(C) Chronic myelogenous leukemia matches (IV) Exchange of a large portion of chromosome 22 with a small fragment from a tip of chromosome 9. This describes the Philadelphia chromosome (t(9;22) translocation), forming the BCR-ABL fusion gene that drives leukemia.
-
(D) Cri du chat matches (II) Deletion in chromosome 5 resulted in small head. A deletion on 5p causes microcephaly (small head), cat-like cry, and developmental delays.
Option Analysis
All four choices are evaluated for accuracy.
Option A Match B Match C Match D Match Correct? 1. (A)-(II), (B)-(I), (C)-(III), (D)-(IV) Wrong (DMD not chr5 del) Correct Wrong (CML not X-gene) Wrong (Cri du chat not CML trans) No 2. (A)-(III), (B)-(I), (C)-(IV), (D)-(II) Correct Correct Correct Correct Yes 3. (A)-(II), (B)-(III), (C)-(IV), (D)-(I) Wrong Wrong (Down not coord loss) Correct Wrong No 4. (A)-(II), (B)-(III), (C)-(I), (D)-(IV) Wrong Wrong Wrong Wrong No Duchenne muscular dystrophy, Down syndrome, chronic myelogenous leukemia (CML), and Cri du chat syndrome represent key genetic disorders tested in exams like GATE Life Sciences. This Duchenne muscular dystrophy Down syndrome CML Cri du chat matching guide breaks down chromosome abnormalities—X-chromosome gene absence, chromosome 21 addition, chromosome 22-9 exchange, and chromosome 5 deletion—for precise List I List II pairing.
Genetic Causes Decoded
Understand each chromosome matching link.
-
Duchenne muscular dystrophy stems from dystrophin gene loss on X-chromosome, causing coordination failure in boys.
-
Down syndrome’s trisomy 21 adds chromosome 21 material, resulting in short stature and developmental issues.
-
CML features Philadelphia chromosome via chromosome 9 tip swap with chromosome 22, activating cancer genes.
-
Cri du chat involves 5p deletion, leading to small head (microcephaly) and cat-like cry.
Exam-Ready Matching Table
Disorder Genetic Cause Duchenne muscular dystrophy X-chromosome gene absence (III) Down syndrome Chromosome 21 addition (I) CML Chr22-Chr9 exchange (IV) Cri du chat Chr5 deletion, small head (II) Correct option: (A)-(III), (B)-(I), (C)-(IV), (D)-(II). Master this for GATE Life Sciences chromosome disorders prep.
-
