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DNA sequencing is often performed to help produce phylogenetic trees or to classify organisms - VCE - SSCE Biology - Question 6 - 2010 - Paper 1
Question 6
DNA sequencing is often performed to help produce phylogenetic trees or to classify organisms. Sections of nuclear DNA from similar organisms are sequenced and compa... show full transcript
Worked Solution & Example Answer:DNA sequencing is often performed to help produce phylogenetic trees or to classify organisms - VCE - SSCE Biology - Question 6 - 2010 - Paper 1
Step 1
Name and describe another DNA method that is used to determine how closely related two species are.
Answer
Name: Microsatellite analysis
Brief description: Microsatellite analysis utilizes repeated sequences of DNA (short tandem repeats, or STRs) that vary in length among individuals. This method is used to assess genetic variation and can effectively determine relationships by examining the number of repeats in these sequences, allowing scientists to infer genetic diversity and relatedness among species.
Step 2
How would the barcode database be used to identify the fish species that had been caught by the fishermen? Provide an example of a situation (other than illegal fishing) when humans would want to identify the fish species.
Answer
The barcode database can be utilized to match gene sequences from the fish caught with sequences stored in the database. By sequencing a small portion of the fish (like the cox1 gene) and comparing it against the database, scientists and researchers can accurately identify the species.
An example of a situation where fish species identification is important could be during ecological surveys where researchers need to monitor biodiversity and assess the health of aquatic ecosystems, helping to inform conservation strategies.
Step 3
Explain what redundancy in the genetic code means.
Answer
Redundancy in the genetic code refers to the phenomenon where multiple codons (triplets of nucleotides) can code for the same amino acid. As a result, even if there is a mutation in one of the codons, the same protein may still be produced, which adds a layer of robustness to genetic expression. This redundancy helps buffer against potential harmful effects of mutations.
Step 4
Why is it important to sequence multiple samples from the same species?
Answer
It is important to sequence multiple samples from the same species to ensure accuracy of results. By analyzing diverse genetic samples, researchers can capture the genetic variability and evolutionary adaptability of the species, which aids in a more comprehensive understanding of the species’ genetics and assists in identifying any potential conservation needs.