Examine model 2. number the steps below in order to describe the replication of dna in a cell. hydrogen bonds between nucleotides form. hydrogen bonds between nucleotides break. strands of dna separate. free nucleotides are attracted to exposed bases on the loose strands of dna.

1) Hydrogen bonds between nucleotide break
[the enzyme helicase breaks the hydrogen bonds between the 2 adjacent DNA strands first]

2) Strands of DNA separate
[This exposes the template strand used for the synthesis of a new DNA strand]

3) Free nucleotide are attracted to exposed bases on the loose strands of dna
[Free deoxyribonucleotises are recruited to complentary base pair on template strand from 5'to 3'direction by DNA polymerase which reads the template strand from 3'to 5' direction]

4) hydrogen bonds between nucleotide form.
[After new strand of DNA is synthesized, both template strand and new strand annuals by forming hydrogen bonds between each complimentary base pairs, marking the end of DNA replication. ]

temperatures in the atmosphere change with altitude