When a muscle cell receives a signal from a motor neuron, every sarcomere within that muscle cell is activated. The signal moves from the motor neuron to the muscle cell by crossing the synapse. When acetylcholine binds the sodium enters the T tubules and this causes calcium to be released from the sarcoplamic reticulum. Calcium binds to tropomyosin, which allows actin to bind to myosin and each sarcomere contracts. There is nothing and no way to separate individual sarcomeres. They are all activated together.
That is incorrect your brain has same amount of synapses
Answer:
B. About 50,000 years ago
Explanation:
Evidence of ancient archery has been found throughout the world. Although archery probably dates to the Stone Age (around 20,000 BC), the earliest people known to have used bows and arrows were the ancient Egyptians, who adopted archery at least 50,000 years ago for purposes of hunting and warfare.
The reason why nuclear fusion is currently not used as an energy source on Earth is mainly because we're still building the required technology which would enable us to use and have nuclear fusion and harness its power.