I belive the answer is a sand bar!
The first process is called transcription where the DNA's information is used to make mRNA. The second process is called translation where the tRNA comes with an amino acid to drop off. A chain of amino acids will eventually be formed to create a protein. Transcription comes before translation. Think that you have to script something before you can translate it.
The difference between a monogenic inheritance and a polygenic inheritance are the amount of alleles they depend on. A monogenic inheritance depends on only one single allele while a polygenic inheritance depends on multiple alleles. Monogenic refers to qualitative traits and polygenic refers to quantitative traits.
I know all about this, but could you specify what you mean?