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Question 6 To estimate the amount of genetic variation in a species, measures of the average heterozygosity at a number of different gene loci in that species are made - VCE - SSCE Biology - Question 6 - 2002 - Paper 1
Question 6
Question 6 To estimate the amount of genetic variation in a species, measures of the average heterozygosity at a number of different gene loci in that species are ma... show full transcript
Worked Solution & Example Answer:Question 6 To estimate the amount of genetic variation in a species, measures of the average heterozygosity at a number of different gene loci in that species are made - VCE - SSCE Biology - Question 6 - 2002 - Paper 1
Step 1
Which organism would you expect to show the most phenotypic variation? Explain.
Answer
Drosophila would be expected to show the most phenotypic variation because it has the highest average heterozygosity at 12%. Heterozygosity refers to the variability in alleles at a gene locus, and higher levels of heterozygosity can lead to a greater range of phenotypic expression. Since Drosophila has more genetic variation compared to the other species listed, it is likely to exhibit a wider array of traits.
Step 2
Lack of genetic variation is believed to put a species at greater risk of extinction. Explain why low levels of variation put a species at risk of extinction.
Answer
Low levels of genetic variation can reduce a species' ability to adapt to environmental changes or resist diseases. With fewer genetic options, if a disease or environmental change occurs, the entire population may respond similarly, increasing mortality and decreasing the population size. This lack of resilience makes it difficult for the species to survive under changing conditions.
Step 3
Explain what is meant by the founder effect in the context of population genetics.
Answer
The founder effect refers to the reduced genetic diversity that occurs when a small group of individuals establishes a new population. This small founding population may not carry all the genetic variations present in the larger original population, leading to a skewed representation of alleles in the new population. Consequently, this can affect the population’s ability to adapt and survive in its new environment.