To simplify the expression \( y^3 \cdot y^5 \cdot y \cdot y^2 \), we can use the product rule of exponents. The product rule states that when multiplying like bases, we add the exponents. Therefore, we add the exponents of all the \( y \) terms together.
Step 1: Identify the Exponents
We start with the expression \( y^3 \cdot y^5 \cdot y \cdot y^2 \). The exponents of \( y \) are 3, 5, 1, and 2.
Step 2: Apply the Product Rule of Exponents
According to the product rule of exponents, when multiplying like bases, we add the exponents. Therefore, we sum the exponents:
\[
3 + 5 + 1 + 2 = 11
\]
Final Answer
The simplified expression is:
\[
\boxed{y^{11}}
\]