Answer:
External factors include physical and chemical signals. Growth factors are proteins that stimulate cell division. – Most mammal cells form a single layer in a culture dish and stop dividing once they touch other cells.
Explanation:
From Google
The magnetic vehicles will move closer to each other because the magnetic force will pull the vehicles together.
The correct answer is proteins.
Proteins have four structures; (1) primary, (2) secondary, (3) tertiary, and (4) quaternary. Primary structures of proteins are formation of peptides and the peptide bonds between amino acids. Secondary structures of proteins involves the amino acid composition leading to hydrophobic interactions forming either alpha helices or beta sheets. Interactions between secondary structures of proteins will make the tertiary structure which is either soluble (globular) or insoluble (fibrous) proteins. Quaternary structures are the combination of two or more tertiary structures and these are called subunits.
Explanation:
Sorry I can't spell Spanish
