Unlike energy, elements are not lost and replaced as they pass through ecosystems. Instead, they are recycled repeatedly. All chemical elements that are needed by living things are recycled in ecosystems, including carbon, nitrogen, hydrogen, oxygen, phosphorus, and sulfur.
<em>During dna replication, the enzyme dna polymerase adds new nucleotides to the </em><em>3</em><em>'</em><em> end of the sugar in the growing strand</em>
The HOX genes encodes important transcription factors. This factors causes protein to be made that specify cell fate and identify; embryonic primary axis, secondary axis and plays important roles in various tracts development.
