What term is used to describe the relationship between a species and its ecosystem?
a. ecological assortment
b. ecological niche
c. natural positioning
d. natural vocation

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Ascientific idea becomes valid when it is what?

The krebs cycle is also known as the calvin cycle pyruvic acid cycle carbon - oxygen cycle citric acid cycle