What was Anton van Leeuwenhoeks contribution of cell theory?

His cell observations have no indication of the nucleus and other organelles found in most living cells, he made use of a microscope containing improved lenses.

Explanation:

None

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.

cell division is not regulated in tumor cells.