Final answer:
Cells employ strategies like contractile vacuoles, the excretion of excess salts, or the use of rigid cell walls to manage osmotic pressure and water content, conserving H2O in different environments.
Step-by-step explanation:
To conserve H2O in crowded cells, organisms employ various strategies depending on their environment. For example, freshwater protists like paramecia have a contractile vacuole that collects and expels excess water to avoid bursting due to hypotonic surroundings.
Meanwhile, cells like red blood cells can experience crenation (shrinking) in hypertonic environments, where solute concentration outside the cell is higher than inside, leading to water leaving the cell. To prevent such osmotic pressure issues, marine animals might intake high saltwater and excrete the excess salts, while foods can have reduced water activity through the addition of salts or sugars, effectively drawing water out of microbial cells.
Plants and fungi, on the other hand, have rigid cell walls that provide support and help maintain turgor pressure, offsetting potential damage from hypotonic environmental conditions.