Why does competition occur in ecosystems? a. competition never happens in ecosystems b. competition occurs only within populations c. competition happens because resources are limited. d. competition happens only over food

Option C. Competition happens because resources are limited.

Explanation:

When resources are limited in an ecosystem, the species compete with each other to come out as best among all.

As per the theory of natural selection, Darwin proposed that it is always the fittest of all that survive. By fittest he means the ones who are capable to compete and come out as the strongest among all to survive in a given ecosystem.

For Example - Male compete among themselves to attract the female. This is known as sexual selection.

Hence, option C is correct.

"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."

i think the answer would be d