Arrange the events in the order that they occur during DNA replication. Helicase unzips DNA
to separate strands
Topoisomerase unwinds
the coiled DNA
Primase lays down
short RNA strands
Polymerase synthesizes
new DNA strands
The new strands are
glued using ligase.

a- all cells come from pre-existing cells

atp is used for energy.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

the correct answer is 2 and 4