Giving too many points

If the examiner asks for a specific number of points, or if it’s obvious how many points are required, but you’re not sure about one or two of your points, can you give more points than necessary to be sure of getting all the marks?

For example, the examiner asks for 6 tests of controls and I only know 4 but can think of 4 other possibilities, should I write the 4 I’m sure of, then all the others in case only two of them are correct?

Obviously this takes time away from other questions but let’s say I have a few extra minutes. Would writing extra damage my chances of gaining marks?