I believe it's stem cells.
Carbohydrates attached to lipids and to proteins extend from the outward facing surface to the membrane. The second factor that leads to fluidity is the nature of the phospholipids themselves
The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial Revolution. The frequency of dark-coloured moths increased at that time, an example of industrial melanism. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin's natural selection in action, and remains as a classic example in the teaching of evolution. Sewall Wright described it as "the clearest case in which a conspicuous evolutionary process has actually been observed."
Answer:
Proteins range in molecular weight from 1000 to more than 1 million daltons (Da), but the folded size of a globular protein is not necessary correlated to its molecular weight. Proteins composed of about 250 amino acids or less often have a simple, compact globular shape. Larger globular proteins are usually made up of two or more recognizable and distinct structures, termed domains or modules. These are compact, folded protein structures that are usually stable by themselves in aqueous solution. Typical domain structures consist of hydrophobic cores with hydrophilic surfaces. Individual domains often possess unique functional behaviors and often perform unique functions within the larger protein in which they are found.
