Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.
3.5 Molecular Evolution & Phylogenetics — Test 2
Q1. An inactive, faulty copy of a functional gene is called a:✓ Pseudogene
Q2. The molecular clock hypothesis, used to estimate divergence times, is based on:✓ Neutral evolution
Q3. The basic assumption required to use a molecular clock is that:✓ The rate of neutral mutation is approximately constant over time
Q4. Over time, the molecular distance between two evolving lineages increases largely due to:✓ Neutral mutation
Q5. The major mechanism for the evolution of new genes and protein families is:✓ Gene duplication followed by divergence
Q6. Comparing related organisms, sequence variation is generally maximal in:✓ Introns
Q7. The rate of molecular evolution is generally LOWEST for:✓ Non-synonymous (amino-acid-changing) substitutions
Q8. Molecular evolution generally does NOT reflect:✓ Convergent evolution
Q9. If the ratio of non-synonymous to synonymous substitutions per site (dN/dS) is greater than 1, it is evidence of:✓ Positive (Darwinian) selection
Q10. Genes that are similar in sequence and function in two different species because they descend from a common ancestral gene (through speciation) are called:✓ Orthologs
Q11. Genes that arise by duplication within a single genome are termed:✓ Paralogs
Q12. A monophyletic group consisting of a common ancestor and all of its descendants is called a:✓ Clade
Q13. A group of species that are phylogenetically grouped together but do NOT share an immediate common ancestor (the grouping is based on similarity) is termed:✓ Polyphyletic
Q14. A process that strongly interferes with reconstructing phylogeny from gene sequences (because genes move between unrelated lineages) is:✓ Horizontal gene transfer
Q15. The evolution of a multigene family typically occurs by:✓ Both gene duplication and unequal crossing-over
Q16. A prediction of the neutral theory, supported by data, is that humans and chimpanzees differ:✓ More in pseudogene sequences than in functional coding regions
Q17. Which species concept uses both morphological and molecular characters (and shared ancestry) to delimit species?✓ Phylogenetic
Q18. For which feature is convergent evolution LEAST likely?✓ The exact base sequence of a gene
Q19. Phylogenetic relationships among organisms are best established using:✓ Molecular markers (sequence data)
Q20. Match each molecular-evolution term with its description and select the correct option.✓ A-ii, B-i, C-iii, D-iv