An area defined by environmental conditions and natural features is known as O Eco-region
O Ecology
O Succession
O Natural Selection

Eco-region

Explanation:

An eco-region, also known as ecozone, is an ecological area defined by environmental conditions and natural features. An eco-region is defined by conditions such as soil type, temperature etc. Eco-regions have features like soil, that defines its boundaries. Eco-regions can be classified into biomes.

Hence, according to this question, an area defined by environmental conditions and natural features is known as ECO-REGION

well

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."