The cell membrane separates the intracellular environment from the extracellular environment outside of the cell. A phospholipid is composed of a phosphate group and a lipid. It is composed of a hydrophilic, polar phosphate head and two hydrophobic fatty acid tails.
The structure of the bilayer is such that the tails are shielded from contact with water, creating a selectively-permeable barrier which will be impermeable to most hydrophilic molecules.
So, the answer is A) To maintain balance of water and nutrients in the cell.
Population Size and Density: Total size is generally expressed as the number of individuals in a population.
Population dispersion or spatial distribution
Age structure
Natality (birth rate)
Mortality (death rate)
They have served their purpose and are no longer needed by the plant.
Answer:
Lightning is an electric current. Within a thundercloud way up in the sky, many small bits of ice (frozen raindrops) bump into each other as they move around in the air. All of those collisions create an electric charge. After a while, the whole cloud fills up with electrical charges.
