The DNA molecule is shaped like a ladder that is twisted into a coiled configuration called a double helix. The nitrogen bases form the rungs of the ladder and are arranged in pairs, which are connected to each other by chemical bonds.
You’re beautiful/handsome! I hope you have a great day/night ❤️❤️
Answer:
Excitation is the process in which action potentials in the nerve fiber lead to action potentials in the muscle fiber. There is then a rapid fluctuation in membrane voltage at the motor end plate, called the end-plate potential. Areas of the sarcolemma near the motor plate have gates that open, moving ions, which causes the action potential that excites the muscle fiber. The process begins with a nerve signal stimulating a voltage-gated calcium ion channel to open, allowing the ions to enter the axon terminal. The ions stimulate the release of acetylcholine into the synaptic cleft.
The first life form found on earth were mostly bacteria. "For the next 1.3 billion years (3.8 to 2.5 billion years ago), the Archean Period, first life began to appear and the world's landmasses began to form. Earth's initial life forms were bacteria, which could survive in the highly toxic atmosphere that existed during this time."
