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.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.