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.
<span>the high expense; electron microscopes are costly</span>
Answer:
TAA-CTC-GTC-AGT-TTT-AGG-C
Explanation:
A=T
C=G
Explanation:
charles darwin proposed thoery of natural selection.he had collected imnumerable specimens of plant and animals.he published concept survival of fittest. while explaining he says that There is always competition for food.only those organism survive which shows adptations in various reasons. it thoery of natural selection.
There are some objections,
1. natural selection is not only factor responsible for evolution.
2. darwin did not mention uesful and useless modifications.
3. There is no explanation about slow and abrupt changes
Answer:
Explanation:
A moving charge causes a magnetic field and a moving magnet causes an electric field. If you change your frame of reference to that of the charged particle, the magnetic field disappears. Same is true for the magnet. Changing your reference frame to that of the magnet will make the electric field disappear.
