Answer:
A.the flow of energy between organisms in an ecosystem
A cell can only respond to signals from other cells, not from the physical environment. receptor activation. The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on: the presence of the appropriate receptors on the cells of the target tissue or organ.
Answer: Water will leave the cell and the cell will shrink.
Explanation:
Osmosis is the net movement of water from an area of low to high concentration of solutes through a semipermeable membrane. If none of the compartments contains solutes, then the water moves in either direction between the compartments. <u>However, if we add a solute to one of the compartments, this will affect the probability of water molecules leaving that compartment and moving into the other compartment.</u> The ability of water to move into or out of a cell is called tonicity. The tonicity of a solution is related to its osmolarity, which is the total concentration of all the solutes in the solution. A solution with low osmolarity has few solute particles per liter of solution, whereas a solution with high osmolarity has many solute particles per liter of solution. When two solutions with different osmolarities are separated by a membrane permeable to water but not permeable to solutes, water diffuses from the side with lower osmolarity to the side with higher osmolarity. So, solutions can be:
- <u>Hypotonic</u>: The extracellular fluid has a lower osmolarity than the fluid inside the cell, it is hypotonic with respect to the cell, and the net flow of water will be into the cell.
- <u>Hypertonic</u>: The extracellular fluid has a higher osmolarity than the cytoplasm of the cell, it is hypertonic with respect to the cell and water will flow out of the cell.
- <u>Isotonic</u>: The extracellular fluid and the cell have the same osmolarity so there is no net movement of water.
If a cell is placed in a hypertonic solution, water will leave the cell and the cell will shrink due to the difference in pressure and may even die from dehydration.
