5.3 Aneuploidy & Nondisjunction — Test 1

Start Here Introduction ▾

Welcome! 5.3 Aneuploidy & Nondisjunction — Test 1 — 20 questions, CSIR-NET style.

What this test covers

Nondisjunction in meiosis I vs II
Trisomy, monosomy & nullisomy
Down, Patau, Edwards syndromes
Maternal age & aneuploidy

How to use

Tap the test below — it opens on its own full screen. Use ← All tests at the top to come back.
Each question has a 40-second timer. Answer, then Submit to see your score.
Tap 📋 View Solution under any question for a full explanation.

Open Review at the bottom for a quick revision list of every question with its correct answer.

All 20 Questions Review ▾

Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.

5.3 Aneuploidy & Nondisjunction — Test 1

Q1. The failure of chromosomes to segregate properly during meiosis or mitosis, leading to aneuploidy, is called:✓ Nondisjunction

Q2. The failure of separation of sister chromatids during cell division is specifically called:✓ Non-disjunction

Q3. If nondisjunction occurs in meiosis I, the most likely set of gametes is:✓ Two n+1 and two n−1

Q4. If a gamete from nondisjunction at the second meiotic division is fertilised by a normal gamete, the proportion of trisomic progeny (from such gametes) is:✓ 1/2

Q5. A colour-blind son with Klinefelter syndrome (47,XXY) is born to phenotypically normal parents (no crossing over assumed). The nondisjunction occurred during:✓ Female gamete formation in meiosis I

Q6. Aneuploidy is a condition in which:✓ One or more individual chromosomes are missing or added

Q7. The addition of a single chromosome to the karyotype (2n+1) is called:✓ Trisomy

Q8. A nullisomic condition is represented by:✓ 2n−2

Q9. Which karyotype is an example of monosomy?✓ 45, X

Q10. Down syndrome is associated with:✓ Extra chromosome 21

Q11. Trisomy of chromosome 21 is known as:✓ Down syndrome

Q12. An individual with classic (full) trisomy-21 Down syndrome has how many chromosomes in each cell?✓ 47

Q13. Down syndrome is an example of:✓ Aneuploidy

Q14. Patau syndrome is also known as trisomy:✓ 13

Q15. Edwards syndrome is also called trisomy:✓ 18

Q16. Which trisomy karyotype generally has the mildest developmental effect?✓ 47, XXX (triple-X)

Q17. A purely numerical change in chromosome number is exemplified by:✓ Down syndrome

Q18. Maternal nondisjunction of chromosome 21 increases markedly with:✓ Advancing maternal age

Q19. A monosomic individual (2n−1) is usually inviable in humans except when the missing chromosome is:✓ An X chromosome (giving Turner syndrome)

Q20. Match each karyotype change with its name and select the correct option.✓ A-iii, B-i, C-ii, D-iv