If the cell cycle is not completed properly

Improper separation during anaphase results in a cell that has an abnormal number of chromosomes. Anaphase is part of mitosis, or the process of cell division. Anaphase is the time during which chromosomes that are lined up in the middle of a cell are pulled apart in two directions, resulting in two new cells. Errors during anaphase can result in the usual two cells after mitosis or one big cell because the two cells never split apart. In either case, the number of chromosomes is often wrong. There are different types of chromosomal abnormalities, ranging from one extra copy of one chromosome to multiple extra copies of all chromosomes.

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein