Please help :) How does oxygen pass from the blood into the mitochondria?

Please explain :)

Once inside muscle cells, the oxygen can either bind to myoglobin (a protein like hemoglobin that enables muscle cells to store a small amount of oxygen) or enter the mitochondria to be used in the elec- tron transport chain to accept the H+ ions produced by the oxidation of carbohydrate and fat.

Soz if its not very clear, but if u get it correct, can u give me ?

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

in addition to spreading humanist ideas, erasmus has contributed to criticism of corruption in the church.