1. Contraction
2. Actin
3. Tendons
4. Epidermis
5. Dermis
6. Acne
7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.
For Penn Foster.
Answer:
B) detailed record keeping
Explanation:
I just took this test and this was the correct answer.
Answer:
Mutualistic means that both organisms benefit.
Explanation:
The acacia tree provides shelter and food to the ants, while the ants protect the tree from other animals.
Answer:
Nuclei and vacuole
Explanation:
But in animal cell vacuole are temporary exist
