Irritation Threshold is defined as the name applies. It is the threshold or maximum point at which an individual has become irritated or annoyed.
<span>A CO2 molecule found a friendly stomata on the bottom of a leaf. As the sun rose, the leaf's cells opened up to let the molecule in through the stoma. Soon, it was moving around inside with other CO2 and water molecules.
Soon, the plant--powered by the sun--began re-assembling the molecule into new forms, adding and subtracting bits with other molecules, to make sweet glucose and release oxygen into the air.
A curious rabbit couldn't resist a few nibbles of the sweet leaves with their glucose, and soon the CO2 molecule, in its new form as glucose, was inside the bunny's belly, being converted into energy.</span>
The word isotonic is used to refer to the solutions (two solutions) which have the same osmotic pressure in both sides of the semipermiable membrane. The condition allows the free movement of water across the membrane. However, this does not change the concentration of the solution across the membrane.
Hence, osmosis may not occur in this condition.