Down syndrome is caused by trisomy of chromosome 21 (47 chromosomes total).
NEET UG 2020 — Biology Genetics
Down syndrome is due to
Verified 30 May 2026.
Monosomy of chromosome 21
Trisomy of chromosome 21
Trisomy of chromosome 18
Deletion in chromosome 5
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In a dihybrid cross, the phenotypic ratio in F₂ generation is:
In a dihybrid cross between RrYy × RrYy, the phenotypic ratio of round yellow to wrinkled green is:
Which of the following is a sex-linked recessive disorder?
The phenotypic ratio of a monohybrid cross in F₂ generation is:
In Mendel's monohybrid cross, the phenotypic ratio in F₂ generation is:
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