IB Biology SL A3.1.9 Diversity of Eukaryote Genomes Questions
Interpret gene-count and segmental-duplication data to compare eukaryote genomes and explain lineage-specific differences.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Exam points
- Interpret gene-count and segmental-duplication data to compare genome diversity between eukaryote lineages.
- Explain how duplication, mutation and divergence create lineage-specific or shared genome regions.
IB Biology SL A3.1.9 Diversity of Eukaryote Genomes Questions question 1
Analysis of the genome of primates reveals many DNA segments that have been duplicated. It is possible to deduce the stage in evolution at which segmental duplications (SDs) occurred by comparing human and other primate genomes. Human-specific SDs occurred after humans and chimpanzees diverged. Human-chimpanzee shared SDs occurred after the common human-chimpanzee ancestor diverged from gorillas and so on. It is possible to estimate the rates at which SDs occurred during evolution using knowledge of when the primates changed. In the chart the bars indicate numbers of shared SDs and the line shows estimates of the rate of SDs per millions of years (Myr).
Question (a)
(a)
State the number of SDs that can be found in humans but not in other primates.
[ 1 ]
Question (b)
(b)
State the rate of SDs after the divergence of macaques from the other primates, giving the units.
[ 1 ]
Question (c)
(c)
Outline the trends in the rate of SDs occurring since the separation of orangutans from other primates.
[ 2 ]
Question (d)
(d)
Explain how the number of human-chimpanzee shared SDs can be the lowest despite the rate of SDs per millions of years being the highest.
[ 2 ]
Question (e)
(e)
A few SDs were found in humans and gorillas but not chimpanzees. Suggest how this might have occurred.
[ 1 ]
All question bank results loaded