Answer:
Explanation:
A gene can be turned on or off by environmental factors or from other cells that activate proteins known as transcription factors.
Answer: C) Apical
Explanation: An epithelium has a free surface, the apical surface, exposed to the outside, and an attached surface, the basal surface, resting on the underlying connective tissue.
I believe the correct answer is acid rain.
The answer is bioaccumulation. Bioaccumulation is when toxins build up in a food chain. The animals at the top of the food chain are affected most severely because the concentration of toxin becomes most concentrated in the body tissues of the animals at the top of the food chain.
