The major function of the contractile vacuole of amoeba is osmoregulation. The solute concentration found in the cell of amoeba's cytoplasm is more than the solute concentration in the freshwater that surround the external part of the organism, thus, water enter the cell through osmosis. The contractile vacuole collect the excess water and expel it through an opening in the cell membrane. By doing this, the contractile vacuole maintains the water balance in amoeba. This how the contractile vacuole normally operate.
In a situation where amoeba is placed in seawater, then water from the cell cytoplasm will rush out of amoeba cell, because of the higher salt content of the surrounding medium. The contractile vacuole will respond to the situation by increasing its contraction and pumping water out the cell in an accelerated manner, this will lead to the shrinking of the cell.
Answer: the answer is (d)
Explanation:
Big growth is
<span>macroevolution as small growth is to microevolution</span>
The geosphere is considered that portion of the Earth system that includes the Earth's interior, rocks and minerals, landforms and the processes that shape the Earth's surface. The geosphere may be taken as the collective name for the
- hydrosphere (The hydrosphere is the liquid water component of the Earth. It includes the oceans, seas, lakes, ponds, rivers, and streams. The hydrosphere covers about 70% of the earth surface)
- cryosphere (The cryosphere is the frozen water part of the Earth system. The Beaufort Sea, north of Alaska. One part of the cryosphere is ice that is found in water),
- atmosphere( is a layer or a set of layers of gases surrounding a planet or other material body)
- lithosphere is the substantial, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure. It is bounded by the atmosphere above and the asthenosphere below. The lithosphere is further subdivided into tectonic plates. The lithosphere is the most rigid of Earth’s layers.
