Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.
5.4 Polyploidy, Special Chromosomes & Cytogenetic Techniques — Test 1
Q1. A condition with more than two complete sets of chromosomes is called:✓ Polyploidy
Q2. When a diploid cell is treated with colchicine, it typically becomes:✓ Tetraploid
Q3. Autopolyploidy represents:✓ More than two chromosome sets, all from the same parental species
Q4. Which crop is an autotetraploid?✓ Potato
Q5. Diploid maize (2n = 2x = 20) treated with colchicine to make a tetraploid showed reduced fertility chiefly because of:✓ Problems (irregular pairing) in meiosis
Q6. The number of chromosomes in the gametes of hexaploid bread wheat (2n = 42) after meiosis is:✓ 21
Q7. If the diploid number in tobacco is 48, the number of chromosomes in a pollen grain (male gamete) is:✓ 24
Q8. Species A has 2n = 18 and species B has 2n = 20. An allotriploid combining their genomes could have:✓ 28 and 29
Q9. Polytene chromosomes are found in the:✓ Salivary glands of Drosophila larvae
Q10. Polytene chromosomes are formed during which phase, due to which process?✓ Interphase; by repeated DNA replication without cell division
Q11. Chromosome puffs (Balbiani rings) occur on:✓ Polytene chromosomes
Q12. Lampbrush chromosomes are found in:✓ Amphibian oocytes
Q13. In lampbrush chromosomes, the structures that actively synthesise RNA are the:✓ Lateral loops
Q14. Chromosome painting (FISH-based karyotyping) relies on:✓ Specific hybridisation with fluorescently labelled probes
Q15. Chromosome painting is also known as:✓ FISH (fluorescence in situ hybridisation)
Q16. A technique used to locate a specific known gene locus on a chromosome is:✓ FISH
Q17. To detect genome-wide rearrangements (translocations, deletions, duplications) in progressing cancer cells, the most appropriate technique is:✓ Multicolour FISH / spectral karyotyping
Q18. Chromosomal banding combined with somatic-cell hybridisation is historically useful for:✓ Assigning a particular gene to a specific chromosome
Q19. Comparative genomic hybridisation (CGH) is mainly used to detect:✓ Genome-wide gains and losses (copy-number changes)
Q20. Match each special chromosome/technique with its feature and select the correct option.✓ A-iii, B-i, C-ii, D-iv