Answer:
Cell–cell interaction refers to the direct interactions between cell surfaces that play a crucial role in the development and function of multicellular organisms. These interactions allow cells to communicate with each other in response to changes in their microenvironment.
Cell definition: the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed.
Cytology definition: the study of cells as fundamental units of living things.
Variations, traits
Not all members of a species are the same. Every species exhibit variations. Traits, like eye color, are passed from parent to offspring.
Genetic variation is the subtle differences in the DNA sequence in each individual’s genomes. Genetic variation results in various forms or alleles of genes that determines distinct traits such as eye color, skin color, shape of face, and hair color that can be passed on from parents to offspring.
I think it may be this but not quite sure
Lipids are primarily hydrophobic in nature, but there are a large variety of lipids such as fatty acids, mono-, di-, and triglycerides, for example (check wikipedia for more examples).
<span>Proteins are polymers of amino acids. </span>
<span>Nucleic acids are polymers of nucleotides.</span>