What do humans , flowers , and bacteria have in common ? Each of them , along with every other organism on Earth , are made up of DNA . Encoded within their DNA are the directions for traits as diverse as the color of a person ' s eyes , the scent of a rose , and the manner in which a bacteria infects its host cell . without nuclei are called prokaryotes . In eukaryotes , DNA is housed within the nucleus . In prokaryotes , DNA is located directly within the cellular cytoplasm . Humans are eukaryotes .
DNA is found in nearly all living cells . However , its exact location within a cell depends on whether the cell contains a nucleus or not .
Organisms composed of cells that contain nuclei are called eukaryotes , whereas those composed of cells
Eukaryote
Prokaryote
THE BUILDING BLOCKS OF DNA
At the most basic level , DNA is composed of a series of smaller molecules called nucleotides .
Each nucleotide is made up of three components :
● a nitrogenous base
● a sugar molecule called deoxyribose
● a phosphate molecule
There are four different DNA nucleotides , each defined by a specific nitrogenous base .