I tend to write my answers in bullet points clearing making a symbol such as * along with each point. Also I tend to leave a blank line and start my next point.
Is this ok? or is a paragraph approach more suitable or perhaps the style doesn’t matter at all?
What examiners do not like is a bullet followed by one or two words: that really explains nothing.
What they do like, in general, is separate paragraphs each of at least a couple of sentences. That is enough to explain and develop what you want to say. Whether or not you precede each paragraph with a bullet is somewhat irrelevant, but it can look non-professional. If you leave a line between each paragraph, a bullet point is superfluous.