Question 19 of 782
The cilia in paramecium are used for
- A. respirating
- B. locomotion
- C. protection
- D. regulating food intake
Correct Answer:
B
Explanation
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.
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The direction of movement can be altered by changing the pattern of ciliary beating, allowing the paramecium to turn or change its swimming direction.
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Why Other Options Are Incorrect:
- A. Respirating: Paramecium does not use cilia for respiration. Instead, respiration occurs through diffusion across the cell membrane. Oxygen enters and carbon dioxide exits the cell directly through the surface, not through ciliary action.
- C. Protection: 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. Other structures, like the pellicle (a flexible outer covering), provide more direct protection.
- D. Regulating food intake: Cilia do assist in feeding by creating water currents that help bring food particles closer to the oral groove, but they do not directly regulate food intake. The actual intake of food occurs through a process called phagocytosis, where the paramecium engulfs food particles.
Summary of Key Points:
- Cilia in paramecium are primarily used for locomotion, allowing the organism to swim and navigate its environment.
- The coordinated beating of cilia creates movement through water, essential for finding food and avoiding danger.
- Other options (respiration, protection, regulating food intake) do not accurately describe the primary function of cilia in paramecium.
Revision Summary:
- Cilia are hair-like structures that enable movement in paramecium.
- They beat in a coordinated manner to propel the organism through water.
- Cilia are not involved in respiration, protection, or directly regulating food intake.
- Understanding the specific functions of cellular structures is crucial for grasping organism behavior and physiology.