Endocrine signaling is hormone based signaling that travels through the blood stream. Many of the sensors and integrating sensors of the endocrine system are located in the brain. The brain barrier contributes to endocrine signalling, such that the brain barrier does not factor in with endocrine signalling. The answer is A
Answer:
A dam that could allow fish to still pass through is a fishway/fish pass its a "fish ladder" that is structured on or around artificial or natural barriers to allow for fishes natural migration and the movement for potamodromous species.
I think it is B. biome
Because biome means a large area dominated by characteristic plants and animals, such as a rain forest, desert, or tundra.
I am pretty sure it's D) use of electrons focused by magnetic fields.
