During my Master Degree,

A friend asked our instructor the following:
Does a Graphic Designer need to know how to draw?

This guy used this question as thesis:P, and in my opinion it is a good question for thesis because a lot of designers do not know how to draw faces, human body, cars... and there is a misperception that if a designer can't draw he might not succeed or he is not a good designer.

Anyhow, this guy left the masters, and he didn't continued his degree, but he has a good question, you might use it in your thesis if you want!

My opinion is the following,
A graphic designer is not an artist like so it is not important if he can draw or not. Graphic designer is a person who project and idea or a message through visual. Artist is a person who draw beautiful things like drawing or a painting. 

if you have a logo job. You take your pencil and start sketching, when you finish then you take the sketches to the pc to refine them and voila:)



But, like every specialties there is branches in graphic design, which are Brand designer, Finalizer, Magazine designer, digital art designer,...
If you can draw you might succeed in digital art and do wonderful poster like below ↓