ConceptConceptDocsDocuments

IB Biology HL 3.1.9 Diversity of Eukaryote Genomes

Practise IB Biology HL 3.1.9 by explaining segmental-duplication rates, divergence intervals and shared genomic differences.

Syllabus
First assessment 2025
Course
Biology HL
Level
HL

Exam points

  • Explain how segmental-duplication rates and divergence intervals affect shared genomic differences.
  • Use comparative genome data to distinguish duplication rate from the number of shared differences.

A3.1.9—Diversity of eukaryote genomes question 1

[Maximum number: 4]

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).

Figure for Question A3.1.9—Diversity of eukaryote genomes question 1 — IB Biology HL

Question (a)

(a)

Outline the trends in the rate of SDs occurring since the separation of orangutans from other primates.

[ 2 ]

Question (b)

(b)

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 ]
All question bank results loaded