When you drop a ball, it is dropped DOWNWARDS so the number is represented by a negative number. If you toss the ball up it will be a positive number.
To answer your question:
When an object is dropped downwards there will be a negative number since the object is falling downwards.
M phase, or mitosis.
(You don't need to know this for your course but more properly cell division could also refer to meiosis or binary fission.)
Oxygen is the primary chemical in the decomposition of organic organisms
