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.
D. is the non-random change in allele frequencies that occurs in a small population.
Answer:
it can not be in 2 sentece
1) Prophase: chromatin into chromosomes, the nuclear envelope break down, chromosomes attach to spindle fibres by their centromeres 2) Metaphase: chromosomes line up along the metaphase plate (centre of the cell) 3) Anaphase: sister chromatids are pulled to opposite poles of the cell 4) Telophase: nuclear envelope .