Which process must occur for a muscle to be able to relax? A. A nerve must initiate an action potential in the muscle fiber.
B. The amount of ATP in the neuromuscular junction must increase.
C. The concentration of calcium in the myofibril must decrease.
D. Myosin and actin must attach to each other.

C. The concentration of calcium in the myofibril must decrease.

I hope this helps.

Based on their location in the atmosphere, the layers are able to have their own special characteristics. for example, most weather occurs in the troposphere. what occurs in each of the other layers? (site 1)

4the indian leaf butterfly has traits that allow it to resemble a leaf. the bright colors of the monarch butterfly indicate that the butterfly tastes bad and can be poisonous. how does the appearance of these butterflies them to survive? f the indian leaf butterfly is able to avoid predators while the monarch butterfly warns predators away. g. the indian leaf butterfly frightens predators away while the monarch butterfly poisons predators before they can eat it. h both butterflies rely on camouflage to avoid predation. j both butterflies cooperate with one another to avoid predation.

Drag the correct tiles to the image. not all tiles will be used. the diagram is a schematic representation of the electron transport mechanism in mitochondria. label the diagram to complete the model.