Answer:
Open channels allow an influx of sodium ions into the cytoplasm of the muscle fiber. The sodium influx also sends a message within the muscle fiber to trigger the release of stored calcium ions. The calcium ions diffuse into the muscle fiber.
Explanation:
I believe group of cells working together and or performing the same task can be categorized also as a specialized tissue.
Answer:
It just seems like you're supposed to give four pieces of evidence of natural selection. If you're still confused, you can always ask your teacher.
Explanation:
