Yes definitions are needed. You need to structure it like an essay
.. eg. I can show you an sample if you have an email adress i'll be able to send some over!!!>
Example although is here!!..
Intro (Brief summary.. like an english intro)
Body 1.)This body will mention positive effects of protection
Body 2.)This body will mention negative effects of protection.
Body 3.) Maybe trends and stats on protection.
I never have an issue with structure, however planning for 5-10mins before the exam is fundamental