this is the structure of the human body. the order goes like this. cells - nucleus - genes - chromosomes - names of chromosomes and order of chromosomes (A B X Y)
each human has 26 pairs of chromosomes. 13 from each parent. defaults in chromosomes cause illnesses like sickle cell anemia and down syndrome.
the human genome project was set up to identify all of the genes and chromosomes in the human body, therefore increasing the likeliness to create drugs and treatment for illnesses such as cancer etc.
information in Mrs Deamon science - biology book