Someone asked this question already and it was answered by @mrsbabyjacob and verified by an expert. Here’s there answer:
“Relaxation occurs when stimulation of the nerve stops. Calcium is then pumped back into the sarcoplasmic reticulum breaking the link between actin and myosin. Actin and myosin returned to their unbound state causing the muscle to relax.”
Another person said they thought the answer was A.
Just don’t want you to accidentally waste your points when there are answers already :)
3. A. They help separate the chromosomes
Spindle fibers attach to chromosomes and pull them towards different poles of the cell during the final phases of mitosis. The result is two identical cells with the same chromosomes.
4. C. A cell plate
A cell plate is a structure found in plant cells on the top and bottom of the cell. It is a perforated wall made of cellulose and it allows for substances to move in and out of the cell, as the outer most layer of a plant cell, the cell wall, is impermeable.
Pacific wide tsunamis are a rare phenomenon, occurring every 10-12 years on average. Tsunamis do not have a season and do not occur regularly or frequently. However, they do pose a major threat to the coastal populations of the Pacific and other world oceans. They are rare Hope this helped!
