Occurred is spelled with two "r"s.
Occur, is spelled right.
The correct spelling is 'occurred'.occurred
OCCURRED: took place or happened ("It occurred on the 4th of march.") ACCRUED : collected over a period of time, accumulated
The past tense is occurred.
The correct spelling is occurred.
The correct spelling is "happens." It is a verb used to indicate things that occur or take place.
That is the correct spelling of "occurrence" (an event).
That is the correct spelling of "recurred" (occurred again).
The correct phrasing is "Did you have a chance." This is the past tense form of the verb "have," used to inquire about an opportunity or possibility that occurred in the past.
"What I did is" is correct. It does not matter that the doing occurred in the past: it is still what I did, and will always be what I did. The answer below represents a very popular misuse of tenses. You are talking about something you did in the past, because you are using "did", therefore the correct statement is, "What I did was..." If you were to use the verb "is" or "to be" then that means you are speaking about the present, so the correct statement using this verb is "What I am doing is..."
The chromosomes would not have replicated, so the resulting daughter cells will not have the correct ploidy.
If a person needs to know which occurred they will also need to include what the answer choices are. Without knowing what is being referred to when it says which, people will not know what one of them is correct.