Which molecule in animal plasma membranes reduces the permeability of the membrane to most biological molecules?
(a) proteins
(b) phospholipids
(c) glycolipids
(d) nucleic acids
(e) cholesterol

The correct answer is option 'e' : Cholesterol

Explanation:

The ease at which materials can be transported across a membrane depends on the membrane permeability. Membrane permeability is basically the ease at which materials are transported across membrane . As we know that upon increasing the viscosity of any fluid it's resistance to deformation increases or it applies a greater resisting force if we try to change the shape of the membrane thus reducing the permeability of the membrane. the increase in cholesterol increases the viscosity of the membrane thus reducing it's permeability.

complete the square on the right side of the equation;

-5(x + 0)^2 + 15

answer: d. y = -x^2 + 15

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."