In protozoa like Amoeba and Paramecium ,an organ found for osmoregulation which is: 1)contractile vacuole 2)mitochondria 3)nucleus 4)food vacuole?

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In amoeba and paramecium..organ found for osmoregulation is contractile vacuole .option 1

Answer

Osmoregulation is the process of regulating the water balance inside the body of protozoans. This is done with the help of contractile vacuoles. It is absent in marine and parasitic protozoans. In amoeba and paramecium, the contractile vacuole is present for the regulation of water balance.

So, correct answer is 'Contractile vacuole'...

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Answer

**Osmoregulation in Protozoa**

Protozoa are unicellular organisms that belong to the kingdom Protista. They exhibit a wide range of structures and functions, including osmoregulation, which is the regulation of water and solute concentrations within their cells. In protozoa like Amoeba and Paramecium, osmoregulation is primarily carried out by a specialized organelle called the contractile vacuole.

**1) Contractile Vacuole:**
The contractile vacuole is responsible for maintaining the osmotic balance in protozoa. It is a specialized organelle that collects excess water and waste products from the cell and periodically expels them. The contractile vacuole acts as a water pump, actively pumping out water to prevent the cell from bursting due to osmotic pressure.

**Structure and Function of Contractile Vacuole:**
- The contractile vacuole consists of a spherical or elongated cavity surrounded by a membrane.
- It is connected to the cytoplasm through a series of canals or tubules.
- The vacuole fills with water by the process of endocytosis, where water is actively transported into the vacuole.
- Once filled, the contractile vacuole contracts, expelling the excess water through a pore in the cell membrane.

**Mechanism of Osmoregulation:**
- The cytoplasm of protozoa like Amoeba and Paramecium is more concentrated than the surrounding environment.
- As a result, water tends to diffuse into the cell by osmosis, creating a potential risk of cell rupture.
- The contractile vacuole actively collects excess water and waste products from the cytoplasm through its canals.
- The water-filled vacuole gradually increases in size until it reaches a threshold level.
- At this point, the contractile vacuole contracts, expelling the excess water through the pore in the cell membrane.
- The process of filling and contracting of the contractile vacuole is repeated periodically to maintain osmotic balance.

**Other Organelles and Their Functions:**
While the contractile vacuole is primarily responsible for osmoregulation, other organelles in protozoa serve different functions:
- Mitochondria: Mitochondria are the powerhouses of the cell, responsible for generating energy through cellular respiration.
- Nucleus: The nucleus contains the genetic material of the cell and controls its activities.
- Food Vacuole: Food vacuoles are involved in digestion and the storage of nutrients in protozoa.

In conclusion, the contractile vacuole is the organ found in protozoa like Amoeba and Paramecium that is responsible for osmoregulation. It actively collects excess water and waste products from the cytoplasm and periodically expels them, preventing the cell from bursting due to osmotic pressure. Other organelles such as mitochondria, nucleus, and food vacuoles have different functions within the cell.

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