1.6.6Inquiry Process
Uses of Genome Sequencing — IB Biology HL Revision Notes & Topical Questions
5 min read 5 parts Lesson 20 of 160
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Part 1 of 5Understanding Relationships
A genome sequence is a permanent record that can be compared between individuals and species.
Comparing species
- Comparing species Counting base differences between genomes shows how recently two species shared a common ancestor.
Gene discovery
- Gene discovery Matching sequences against known genes helps locate genes and predict the proteins they code for.
Conserved genes
- Conserved genes Sequences that stay almost identical across species are likely to have essential functions.
Evolutionary history
- Evolutionary history Genomes preserve evidence of ancient events such as gene duplication and the fusion of chromosomes.
Part 2 of 5Medical Uses
Medical Uses
Disease risk
- Disease risk Finding alleles linked to disorders lets people learn their risk and take preventive action.
Personalised medicine
- Personalised medicine Knowing a patient genotype can help doctors choose drugs and doses that work best for that person.
Cancer treatment
- Cancer treatment Sequencing a tumour reveals the mutations driving it, guiding the choice of targeted therapy.
Pathogen tracking
- Pathogen tracking Sequencing viral or bacterial genomes shows how an outbreak spreads and where new variants arise.
Part 3 of 5Conservation and Other Uses
1
Sequencing endangered species reveals how much genetic diversity remains and whether inbreeding is a threat.
2
Breeding programmes use the data to pair individuals that are least closely related.
3
Forensic scientists compare DNA from a crime scene with samples to identify individuals.
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Agricultural scientists find genes for disease resistance and yield to improve crops and livestock.
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Sequencing unknown organisms from the environment helps to discover and name new species.
| Field | Use of sequence data |
|---|---|
| Classification | Build family trees from base differences |
| Medicine | Predict disease risk and drug response |
| Conservation | Measure genetic diversity |
Part 4 of 5Worked Example
Question Explain how genome sequencing could be used to show that the giant panda is more closely related to bears than to raccoons.
- Sequence the whole genomes or selected genes of the panda, bears and raccoons.
- Align the sequences and count the base differences between each pair of species.
- The species with the fewest differences shared a common ancestor most recently.
- Panda DNA matches bear DNA more closely than raccoon DNA, so the panda is placed with the bears.
Answer Fewer sequence differences between panda and bears show a more recent common ancestor, so they are more closely related.
Part 5 of 5Exam Checklist & Tips
1.6.6 – Key Points for the Exam
- Genome sequencing Determining the order of all bases in a genome.
- Genotype The alleles carried by an individual.
- Personalised medicine Treatment tailored to an individual genome.
- Genetic diversity The variety of alleles in a population.
Common Mistakes
- Saying a genome sequence predicts every characteristic with certainty; environment also matters.
- Confusing sequencing with gene editing.
- Believing a high number of differences means closer relationship.
- Forgetting ethical issues such as privacy of genetic data.
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