The use of oxygen-18 (heavy oxygen) has aided biologists in determining that o2 released in photosynthesis comes from the chemical breakdown of water. which organisms did the biologists most likely use in their investigation? a algae b paramecium c arthropods d fungi

The correct option is A. Algae

Explanation:

Algae is the best possible answer because the process of photosynthesis can be carried out only by plants, algae and cyanobacteria.  Hence, option A is correct. These organisms are called autotrophs as they are capable of making their own food.

Other organisms like paramecium, arthropods and fungi are not capable of photosynthesis. These organisms like arthropods are called heterotrophs. They do not make their own food and feed on other organisms for food.

for 8 am not sure maybe yes?

for 9 if it is asking if the male is more or less it would be less

hope i even just a little : )

"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."