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Flatworms are animals that live in freshwater streams - Edexcel - GCSE Biology - Question 6 - 2013 - Paper 1
Question 6
Flatworms are animals that live in freshwater streams. 20 flatworms were placed in the centre of a tray containing water. The tray had black and white squares painte... show full transcript
Worked Solution & Example Answer:Flatworms are animals that live in freshwater streams - Edexcel - GCSE Biology - Question 6 - 2013 - Paper 1
Step 1
Calculate the percentage of flatworms found on the black squares.
Answer
To calculate the percentage of flatworms on the black squares,
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Count the total number of flatworms on the black squares.
- In the diagram, count the flatworms that are placed on black squares.
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Then, use the formula for percentage:
- Assuming there are 8 flatworms on black squares: .
Step 2
Step 3
Suggest why this behaviour may help flatworms survive in the streams where they live.
Answer
This innate behaviour may help flatworms survive by enabling them to minimize exposure to predators. By instinctively staying in black areas, they can blend into the environment, making it harder for predators to spot them, thereby increasing their chances of survival.
Step 4
Explain why animals use a variety of signals to communicate.
Answer
Animals use a variety of signals to communicate for several reasons:
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Different contexts: Various situations require specific types of communication. For example, during courtship, animals may use visual displays, sounds, or chemical signals to attract mates. Peacocks display their colorful feathers, while some insects release pheromones to signal readiness to mate.
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Environmental adaptation: Different environments call for different communication methods. In dense forests, visual signals may be less effective; hence, auditory signals or scents may be more beneficial.
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Audience differentiation: Animals may need to communicate with different species or groups within their species. For instance, alarm calls may vary to alert different species about predators, ensuring appropriate responses.
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Complex messages: A combination of signals may convey more complex messages and emotions, such as distress, happiness, or territoriality, allowing for nuanced communication.