Red blood cells exchange carbon dioxide for oxygen
Clown fish and sea anemones.
The answer is the first one: “...attract each other.”
Topoisomerase is the enzyme that can be added to correct the untwisting that is led to strain ahead of the replication fork.
European rabbits (Oryctolagus cuniculus) were introduced to Australia in the 18th century with the First Fleet and eventually became widespread. Such wild rabbit populations are a serious mammalian pest and invasive species in Australia causing millions of dollars of damage to crops.
