In mammals and amphibians? An enucleated egg, a donor nucleus (preferably from an early developmental stage such as a blastocyst), and a means to stimulate the egg to be activated as if it had just been fertilized (poking with a needle is sometimes enough)
Or cloning into a vector as in at the level of DNA?
A vector with positve and negative selection markers (like antibiotic resistance and drug susceptibility), an insert, DNA ligase and restriction enzymes, buffer for restriction and ligation. Or if you are doing cloning by PCR, then you need primers, template, nucleotides, RNA pol like Taq polymerase etc.
The answer to this question would be the second option or B (The moon's orbit is closer to Earth.) because there are multiple different high tides that are caused by either the moon being unusually close to the Earth or the moon is at it's Quarterly or New Moon phases.
Hope that this helped you! :D
The reactant is the chemical reaction of 2 or more different elements.
The product is what is formed in a chemical reaction.
Example: H + O ----> H2O
H + O is the reactants, and H2O is the products.