The extracts below are from a series of blogs written by staff at the Two Oceans Aquarium, Cape Town, about pyjama catsharks and sevengill cowsharks - NSC Marine Sciences - Question 3 - 2021 - Paper 2
Question 3
The extracts below are from a series of blogs written by staff at the Two Oceans Aquarium, Cape Town, about pyjama catsharks and sevengill cowsharks.
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Worked Solution & Example Answer:The extracts below are from a series of blogs written by staff at the Two Oceans Aquarium, Cape Town, about pyjama catsharks and sevengill cowsharks - NSC Marine Sciences - Question 3 - 2021 - Paper 2
Step 1
What adaptation is mentioned in paragraph 1 AND explain how catsharks are able to find their food?
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Answer
The adaptation mentioned is the catsharks' sensitivity to chemicals and touch, enabling them to detect food. They are able to find their food primarily through their ability to sense edible substances nearby, which is facilitated by their heightened sensory organs.
Step 2
Which adaptation of their eyes enables them to hunt equally effectively in bright daylight if they sense edible food nearby?
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Answer
Their pupils can change size and constrict, allowing their eyes to function effectively in varying light conditions.
Step 3
How does the eye of a bony fish differ from that of a shark?
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Answer
The eye of a bony fish cannot change size, whereas sharks have more flexible eyes that can adapt to different light conditions.
Step 4
How are they different from bony fish, which are also oviparous, in this reproductive strategy?
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Answer
Catsharks do not have a defined breeding season, unlike many bony fish. Furthermore, bony fish may not have internal fertilization, while catsharks internalize this process.
Step 5
Name TWO other strategies AND explain how the embryos are nourished while they develop.
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Answer
Other strategies include viviparity, where sharks nurture embryos via a placenta, and ovoviviparity, where embryos develop in eggs inside the mother but hatch within her body. In both cases, the embryos receive necessary nutrients during their development.
Step 6
What is meant by an apex predator?
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An apex predator refers to a species that sits at the top of the food chain, having no natural predators of its own.
Step 7
Why has the author used this example to emphasise the statement?
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Answer
The author uses the example of the great white shark to highlight its significance as a dominant predator in its ecosystem, underscoring the importance of apex predators in maintaining ecological balance.
