The correct option is
B. locomotion.
Detailed Explanation:
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Understanding Cilia: Cilia are tiny, hair-like structures that protrude from the surface of many eukaryotic cells, including those of paramecium. They are made up of microtubules and are capable of beating in a coordinated manner.
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Function of Cilia in Paramecium: In paramecium, cilia play a crucial role in movement. The coordinated beating of cilia allows the organism to swim through water. Paramecium moves by creating a wave-like motion with its cilia, which propels it forward. This movement is essential for the paramecium to navigate its aquatic environment, find food, and avoid predators.
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Mechanism of Locomotion:
- The cilia beat in a specific pattern: they move in a coordinated fashion, with some cilia moving forward while others recover. This creates a propulsion effect.
- The direction of movement can be altered by changing the pattern of ciliary beating, allowing the paramecium to maneuver effectively in its environment.
Why Other Options Are Incorrect:
- A. Respirating:
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Cilia are not involved in respiration. In paramecium, gas exchange occurs through diffusion across the cell membrane. The organism absorbs oxygen and releases carbon dioxide directly from the surrounding water, not through cilia.
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C. Protection:
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While cilia can help in some protective functions, such as moving debris away from the cell surface, their primary role in paramecium is not protection. Paramecium has other mechanisms, such as its pellicle (a flexible outer covering), that provide structural support and some level of protection.
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D. Regulating Food Intake:
- Cilia do assist in feeding by helping to create water currents that direct food particles toward the oral groove of the paramecium. However, this is not their primary function. The actual intake of food occurs through a process called phagocytosis, where the paramecium engulfs food particles, which is distinct from the locomotion function of cilia.
Summary of Key Points:
- Cilia in paramecium are primarily used for locomotion, allowing the organism to swim and navigate its environment.
- They beat in a coordinated manner to create movement, propelling the paramecium forward.
- Other options (respiration, protection, regulating food intake) do not accurately describe the primary function of cilia in paramecium.
- Understanding the specific roles of cellular structures like cilia is crucial for grasping how single-celled organisms interact with their environment.