Cytoplasm is all material (organelles, enzymes, fluid) inside of the cell membrane, except for the nucleus, which has it's own membrane and nucleoplasm within.
The purity of the wavelength of a visual stimulus determines the perceived saturation, or richness, of the stimulus. Wavelength is the distance from the peak of one wave to the next. Stimulus is a change in the environment and the reaction of the organism to it is the response.
Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
The best answer to go with is b
Answer:
The hydrophilic part of the cell membrane is A, the phosphate head.
Charged molecules, such as K+ or Ca++ are unable to pass through the lipid bilayer because of their charge and must use a membrane protein to cross the cell membrane.
C, the lipid tails, are hydrophobic and repel water.
