Answer:
South Texas rather this answer, sorry if not, but I remember that this is the answer
As we inhale air, oxygen enters the respiratory system and the circulatory system to transport it to the other parts of the body and to all cells. As the oxygen is already transported, the blood becomes deoxygenated and carries a CO2 which returns to the lungs and then we exhale the carbon dioxide.
Puberty or a more specific aspect of puberty
Restriction enzymes and or restriction endonucleases are involved at recognizing specific sequence of nucleotides and cutting or splicing them at appropriate regions to produce fragments that can either be sticky ends or blunt ends depending on where they cut and the nature of nucleotides involved within the fragments. They play an important role in genetic engineering, as geneticists can use them for placing into extra chromosomal information and or content of plasmids in certain bacteria, from other sources, for instance antibiotics, grow and or produce many individual colonies of bacteria, isolate them and one would have many sequences for instance that can code for an antibiotic that can be extracted and used further. Assuming the bacteria's plasmid can take in that sequence.