Cold water is denser than warm water
If one population dies out, all the populations that depend on that species for food may also die out. A change in one population affects the entire community because all the populations of a community depend on each other. A population is all the members of one type of organism living in an ecosystem.
I would look up a picture on gogle, if i were you.
Answer:
The root hair cells have carrier proteins in their cell membranes. These pick up the mineral ions and move them across the membrane into the cell against the concentration gradient . ... Because active transport moves ions against the concentration gradient into the root hair cells, energy is needed.
Definitely D because genetically engineered organisms have their genes altered to only contain the desirable or favorable trait that will reap the most benefits. Hope that helps