Question

Why is it hard to see the plasma membrane in plant cells?

Answer 1

There's a cell wall in the way

Explanation:

There is a more structured cell wall surrounding the plant
It covers the while plant cell including the smaller plasma membrane. It's made up of cellulose and pectin. While it's great for the cell in terms of protection and structure, it's bad for us trying to get a look at it what's directly underneath it.