You can go straight into the answer for subjects like business... like the 2-3 mark questions. But for questions with 4+ marks up for grabs, you better put an intro to make it sound better.
EG: Whats the factors that influence _______?
Ans: the factors that influence ______ is blablalbalblalbalblabla
There's really no harm in writing that... but when they ask for like.. explain 2 reasons why ____, you should also put a dot point on the side of your answer so the markers can easily distinguish the two.
I always start off my sentences so it looks like its addressing the questions. My chemistry teacher says to always answer in full, that is.. if you want full marks lol
What I find that works (for me at least), is to write everything you can to make it sounds like a more 'sophisticated' answer, I always go BEYOND the lines they give you. My economics teacher also told me, it's hard for students to get full marks if they only JUST fill up the lines or write less than the lines.