Tikz graph example

centraldogma.tex

\documentclass[tikz,border=14pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}
%\usepackage{xcolor}
\begin{document}
 \begin{tikzpicture}
\node[draw, rounded corners, fill=gray!10](dna) at (0,0){DNA};
\node[draw, rounded corners, fill=gray!10, right = of dna, xshift = +15pt](rna){RNA};
\node[draw, rounded corners, fill=gray!10, right = of rna, xshift = +15pt](protein) {protein};
\node[draw, rounded corners, fill=gray!10, right = of protein](phenotype) {phenotype};
%path
\path[draw, ->, olive](dna)--(rna) node[midway, below, yshift = -10pt]{transcription};
\path[draw, ->, olive](rna)--(protein) node[midway, below, yshift = -10pt]{translation};
\path[draw, dashed, ->, olive](protein)--(phenotype);
%omics
\node[below= of dna](genomics){genomics};
\node[below= of rna](transcriptomics){transcriptomics};
\node[below= of protein](proteomics){proteomics};

\path[draw, teal](dna)--(genomics);
\path[draw, teal](rna)--(transcriptomics);
\path[draw, teal](proteomics)--(protein);

\path[draw, teal](genomics.north west)--(proteomics.north east);
\path[draw, teal](genomics.south west)--(proteomics.south east);
\path[draw, teal](genomics.north west)--(genomics.south west);
\path[draw, teal](proteomics.north east)--(proteomics.south east)node[right](omics){omics};
\end{tikzpicture}
\end{document}