Why is it important that our sex cells only contain one set of chromosomes instead of two sets of chromosomes

It  is important that a gamete or sex cells have exactly only one set of chromosome because during sexual reproduction two sex cells of the parents will form the zygote and it will have 2n or diploid number of chromosomes. It is from this zygote somatic cells are formed.

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.