Selectively permeable (or semi permeable) means where for example a membrane can choose what material can pass through while others cannot. They control the in and out of materials.
This is because the membrane has tiny spaces, where only smaller molecules can pass through, other larger ones cannot.
Answer:
When a substrate is added in water, the enzyme will cause the substrate to dissolve in water. Increase in temperature will cause better functioning of the enzyme and more solute to be dissolved until an optimum temperature. Optimum temperature can be described as the temperature at which the activity of the enzyme is highest.
After optimum temperature is reached, the enzyme will get denatured and the substrate will no longer be able to dissolve in water.
The answer top the question given above is letter c. Surface currents.
There are two types of ocean currents, surface current and deep currents.
Surface currents which are caused by winds,move warm water
away from the equator and cool water away from the poles. Deep currents on the other hand are driven by differences in water density.
2 is correct all animals have a similar goal is survive and reproduce