Which of the following statements is a correct distinction between autotrophs and heterotrophs?
a. autotrophs, but not heterotrophs, can nourish themselves beginning with co2 and other nutrients that are inorganic.
b. only heterotrophs require chemical compounds from the environment.
c. cellular respiration is unique to heterotrophs.
d. only heterotrophs have mitochondria.

a. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.

or

b. Only heterotrophs require chemical compounds from the environment.

i got something better   a catchphrase here it is

ahem  

ahem

what the squwock

explanation:

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."