<span>sperm, blood, hair with attached tissue</span>
Probably C. For example, you can tell how many amount of organism are in an ecosystem if you just check like a lot of animals live in hot climates while not many animals live in cold types of climates. I’m probably not making sense but I would put C.
Answer:These contractile elements are virtually identical to skeletal muscle. ... (a) Cardiac muscle cells have myofibrils composed of myofilaments arranged in sarcomeres, ... The refractory period is very long to prevent the possibility of tetany, a ... At this point, the calcium ion channels close and K+ channels open, allowing outflux ..
Explanation:
The answer is B because they are very rare