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The platypus (Ornithorhynchus anatinus) is a semi-aquatic animal, historically present in rivers throughout Victoria - VCE - SSCE Biology - Question 10 - 2023 - Paper 1
Question 10
The platypus (Ornithorhynchus anatinus) is a semi-aquatic animal, historically present in rivers throughout Victoria. Platypuses usually occur in areas that have st... show full transcript
Worked Solution & Example Answer:The platypus (Ornithorhynchus anatinus) is a semi-aquatic animal, historically present in rivers throughout Victoria - VCE - SSCE Biology - Question 10 - 2023 - Paper 1
Step 1
a. Give two examples of possible sources of eDNA from the platypus.
Answer
Examples of possible sources of eDNA from the platypus include:
- Fur: The platypus sheds its fur into the water, which can be a source of DNA.
- Saliva: Particles of saliva may also enter the water as the platypus feeds.
Step 2
b. Explain two factors to consider when sampling the water to reduce sources of error.
Answer
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Prevent Contamination: It's essential to prevent contamination of DNA from other sources by using sterile equipment and wearing gloves during collection.
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Consistent Sampling Conditions: Ensure that the samples are collected consistently, considering factors like water temperature and the volume of water to increase reliability and validity.
Step 3
Step 4
d. Referring to the project, state one difference between predicted occurrences and detection of platypus presence from the eDNA survey results. Justify your response.
Answer
The main difference is that predicted occurrences (shown with circles) are areas where the platypus was expected to be found based on prior data or models, whereas actual detections (shown with triangles) are areas where eDNA analysis confirmed the presence of the platypus.
Justification: Predicted areas may include regions thought to be suitable for platypus habitation but could have been empty due to habitat destruction or changes in environmental conditions.