The answer may be A look man im just here for the points
Answer:
C.Because of hunting, species such as bears and wolves are in danger of extinction.
It is the same as creating more pests or setting up dominant species which upset the ecological food pyramid leading to decimation of trophic levels or predators and energy cycling. Fishes feed on microscopic algae and animals the primary base of the food chain in water, if they are not checked they will choke the rivers and oceans causing toxic waters. Fish feed to contain them, in the process they grow and increase in numbers but their population is checked by bigger fishes and so on till it reaches a top predator which is usually a large animal.
I believe the answer is B, primary active transport. Root hair cells in plant use active transport to absorb mineral ions such as nitrates from the soil. The concentrations of minerals in the soil are lower in the soil than in within the root hair cell, therefore the transport will be against the concentration gradient which does not favor diffusion, therefore the pant has to use active transport.
Infection, which are antigens that harm your body.