Cholesterol
The animal plasma membrane is a layer of phospholipids that is entwined with cholesterol and proteins. Cholesterol makes up a small part of the cell membrane's mass and it is present in every cell of the body. Cholesterol maintains the integrity of the cell membrane. It assists in the immobilization of the outer surface of the cell membrane and it reduces the permeability of the membrane to most biological molecules. Cholesterol also perform roles in cell signaling, maintaining fluidity and protecting important proteins in the membrane.
<span>Serous Membrane
This is a thin film that lines the interior body depressions and organs, for example, the heart, lungs, and stomach cavity. The thin film is comprised of mesothelium tissue which starts from the mesoderm. The serous film takes into consideration frictionless motion in various indispensable organs.</span>
I think it is A but i am not sure
Variations can be genetic or environmental, the traits are passed from one generation to other generation of snail is from from both parents to offspring and through the environment.
The correct answer is C.
Explanation:
Genetic variation in an organism is passed to the offspring by its parents.
environmental variation is the the result of different environment with which individual adapt.
Natural selection is a process in which a suitable trait which is well adapted to the environment is passed on tho future generations.
Genetic variation is the change in DNA or gene of the individual trait. The tree snails having different pattern in their shells is due to the habitat they are living in.
The snails which have well adapted to the environment are able to reproduce and pass on the traits to their progeny. The variation is due to the traits passed from parents through the environment also.