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Clownfish and starfish are both referred to as fish, which indicates their relatedness and that their life functions have substantial similarities - NSC Marine Sciences - Question 4 - 2022 - Paper 2
Question 4
Clownfish and starfish are both referred to as fish, which indicates their relatedness and that their life functions have substantial similarities. In an essay, cri... show full transcript
Worked Solution & Example Answer:Clownfish and starfish are both referred to as fish, which indicates their relatedness and that their life functions have substantial similarities - NSC Marine Sciences - Question 4 - 2022 - Paper 2
Step 1
State your opinion with a motivation whether the above statement is valid.
Answer
The statement claiming that starfish and clownfish are related due to their shared label as 'fish' is partially valid but ultimately misleading. While both organisms inhabit similar environments, they belong to entirely different phyla, which speaks to their distinct morphological and physiological traits. The classification as 'fish' oversimplifies their differences and obscures the complexities of their evolutionary histories.
Step 2
Discuss, in detail, symmetry and external structures of both organisms.
Answer
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Symmetry:
- Clownfish exhibit bilateral symmetry, meaning their bodies can be divided into two identical halves on either side of a central axis. In contrast, starfish possess a form of pentaradial symmetry, developing this after their larval stage, which allows them to function effectively in their marine environment.
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External Structures:
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Starfish:
- Starfish have skin covered by ossicles, which are hardened calcium carbonate structures. Their skin is supported by elastic collagen fibers and muscles, making it capable of both rigidity and flexibility.
- They have a unique water-vascular system that aids in movement and feeding.
- Each arm contains an ambulacral groove with tube feet (podia) used for locomotion and handling prey.
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Clownfish:
- Clownfish have a streamlined body with bilateral fins, including pectoral, pelvic, dorsal, and caudal fins.
- Their dermal scales provide a mucus layer that helps prevent infection.
- Key adaptations such as an operculum protect their gills, and they possess a lateral line sensory organ that aids in detecting water movement.
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Step 3
Argue if and why it is necessary to classify organisms into different groups.
Answer
Classifying organisms into distinct groups is essential for several reasons:
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Enhances Communication: Accurate classification allows scientists to communicate effectively about organisms, reducing confusion when discussing biodiversity.
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Ecological Validity: Classifications help in understanding the ecological roles of different organisms and their relationships within ecosystems, which is crucial for conservation efforts.
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Identifying Differences: Recognizing the substantial differences among organisms, such as those between starfish and clownfish, is vital for biological research and understanding evolution. It aids in comparative studies which are key to ecological and evolutionary investigations.