Answer
The probability is $\frac{1}{32}$.
Work Step by Step
We know that the probability of having one boy is given below,
$\text{P}\left( \text{one boy} \right)=\text{ }\frac{1}{2}$
And probability of having five boys in a row is:
$\begin{align}
& P\left( \text{five boys in a row} \right)=P\left( \text{one boy} \right)\times P\left( \text{one boy} \right)\times P\left( \text{one boy} \right)\times P\left( \text{one boy} \right)\times P\left( \text{one boy} \right) \\
& =\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\times \frac{1}{2} \\
& =\frac{1}{32}
\end{align}$
