I'm not sure if you needed a translation or an answer but i'll give both:)
"Why is it that in some countries it is day while in others it is night"
because at different times of the day the sun hits different areas of the earth. I hope this helps!
porque en diferentes momentos del día el sol golpea diferentes áreas de la tierra. ¡Espero que esto ayude
Answer:
Explanation:
Limiting factors include a low food supply and lack of space to live in. Limiting factors can lower birth rates, increase death rates, or lead to emigration because of infertile land which is will unable you to grow your own plants. When organisms face limiting factors, they show logistic growth
Answer:
1. Acetylcholine binds to receptors on the motor end plate
2. Ligand-gated channels open leading to depolarization
3. End plate potential triggers an action potential
4. Transverse tubules convey action potentials into the interior of the muscle fiber
5. Calcium is released from the sarcoplasmic reticulum
6. Calcium ions bind to troponin, which then moves tropomyosin
Explanation:
Acetylcholine (ACh) is a signaling molecule (neurotransmitter) that binds to receptors on muscle cells. This binding triggers the opening of ligand-gated sodium channels, thereby ions enter into muscle cells, which causes the depolarization of the sarcolemma and thus promotes the release of Ca2+ ions from the sarcoplasmic reticulum. The myoneural junction, also known as the motor endplate, is the site of synaptic contact between a motor axon and a skeletal muscle fiber. The endplate potential is the voltage that produces the depolarization of muscle fibers when ACh molecules bind to their receptors in the cell membrane. This depolarization spreads in the sarcolemma through transverse tubules (T tubules) and thus generates an action potential. Finally, this action potential induces the release of Ca2+ in the sarcoplasmic reticulum, which activates troponin protein and induces muscle contraction.
