\documentclass[border=10pt]{standalone} 
%%%<
\usepackage{verbatim}
%%%>
\begin{comment}
:Title: A simple Tree
:Tags: Trees;Cookbook
:Author: Stefan Kottwitz
:Slug: tree

A simple tree with a style for all nodes.
\end{comment}

\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw[line width=1pt] (0,0) -- (2,0) ;
\draw[line width=1pt] (-0.75,0.75) -- (1.25,0.75) ;
\draw[line width=1pt] (0,1.5) -- (2,1.5) ;

\draw[line width=1pt] (0,0) -- (-0.75,0.75) ;
\draw[line width=1pt] (-0.75,0.75) -- (0,1.5) ;
\draw[line width=1pt] (1.25,0.75) -- (2,0) ;
\draw[line width=1pt] (1.25,0.75) -- (2,1.5) ;
\draw[line width=1pt] (2.75,0.75) -- (2,1.5) ;
\draw[line width=1pt] (2.75,0.75) -- (2,0) ;

\draw[fill=black] (1.25,0.75) circle (0.1) ;

\draw[black,->] (3,0.75) -- (4,0.75) ;

\draw[fill=white] (6.25,0.75) circle (0.1) ;

\draw[line width=1pt] (5,0) -- (7,0) ;
\draw[line width=1pt] (5.75,0.75) -- (7.75,0.75) ;
\draw[line width=1pt] (5,1.5) -- (7,1.5) ;

\draw[line width=1pt] (5,0) -- (4.25,0.75) ;
\draw[line width=1pt] (4.25,0.75) -- (5,1.5) ;
\draw[line width=1pt] (5.75,0.75) -- (5,1.5) ;
\draw[line width=1pt] (5.75,0.75) -- (5,0) ;
\draw[line width=1pt] (7.75,0.75) -- (7,1.5) ;
\draw[line width=1pt] (7.75,0.75) -- (7,0) ;

\end{tikzpicture}
\end{document}