Suppose a female began menstruating at age 12 and stopped menstruating at age 55. if she never became pregnant and her menstrual cycles averaged 28 days, how many eggs did she ovulate during her reproductive years?

561

Explanation:

This is math so I got you.

This is just going to subtract 12 from 55 since we don't now when during her 12th year of age she started or when during her 55th year f age she ended.

55 - 12 = 43, so about 43 years.  Also not going to account for leap years.  So we are just going to say each year had 365 days.  so 43 years and 365 days per year = 15695 days.

If her cycles were each about 28 days we divide the total number of days by 28 and that tells us about how many cycles there were.

15,695 / 28 = 560.5 which I will round to 561

561 cycles means 561 eggs if my biology knowledge is as accurate as I think it is.  

561 eggs

Explanation: She started menstruating at the age of 12 and stopped menstruating at the age of 55. Since the month of her 12th and 55th anniversary when she started and stopped menstruating respectively were not mentioned, we take the difference between the two anniversaries.

Therefore, 55 - 12 = 43

There is 365 days in a year, so we multiply 43 by 365. 43 x 365 =15,695 days.

Since she has a 28 days cycle, therefore we divide 15695 by 28 ==> 15695/28 = 560.5

561 cycles (rounding off to the nearest whole number accounts for the leap years). 561 cycles is equal to 561 eggs because it is assumed that a woman releases one egg in each cycle.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.