I’ve seen many students drop one (or more!) grades in an extended response because they’ve done great in one section/part, but in the second part they’ve given little to no response.
This can have a huge (and what feel a little unfair) impact when it comes to the mark scheme and gaining credit. But it’s how many mark schemes are structured and therefore better to accept it and have the awareness to combat this nuance!
Allocating time or space in the exam to each part of a response within a question as equally as possible will mean the hard work in one part is not wasted in terms of hitting the mark scheme criteria.