2023TrialShort answer

Q22 (b)

3 marks

Question

The cheetah (Acinonyx jubatus) is a vulnerable species of large cat, known for being the fastest land animal. Since the 19th century, it is estimated that the cheetah population has declined from 100,000 to approximately 8,000 cheetahs. The cheetah faces extinction due to climate change, hunting by humans and habitat destruction. They also have a low rate of reproductive success.
Describe how DNA profiling can be used to show genetic diversity within a population.

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Solution

Criteria	Marks
Describes genetic profiling; defines genetic diversity (or clearly implies it); and describes how profiling can show genetic diversity.	3
Provides two of the above.	2
Provides one of the above.	1

Sample answer:

Genetic profiling typically looks at the number of short tandem repeats (STR) in particular sections of DNA. An individual and their close relatives will have characteristic patterns of STRs at certain loci.
Genetic diversity in a population is an expression of the extent to which different individuals within it carry different alleles.
By profiling a large number of individuals in a population a measure can be made of the degree of genetic diversity in that population. If the profiles obtained show a high degree of similarity, then individuals can be assumed to be closely related and the population to have low genetic diversity. If there is a wide range of profiles then it can be assumed that genetic diversity is high.

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Syllabus alignment

Module 5 · Heredity

Inheritance Patterns in a PopulationInvestigate DNA sequencing and profiling technologies used to determine inheritance patterns.

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