20. which of the following is not a source of genetic variation

In what for do plants utilize nitrogen? why do they need nitrogen?

State officials are considering constructing a road through a forested wilderness area. this action will likely affect the forest ecosystem in various ways. part a: predict how the construction of a road could negatively affect plants and animals in that ecosystem. (3 points) part b: describe one way that the construction of a road could have a positive impact of the forest ecosystem. (1 point)

In which layer do organisms on earth love?