The structures in this list best represent a plant cell.
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Velocity can vary as long there is specific direction (displacement)
Speed has no direction therefore change in speed is not necessary the velocity...
Velocity is also in a specified direction
Answer:
A) the concentration of calcium ions in the sarcoplasm of a resting muscle
Explanation:
Sarcoplasmic reticulum is a system of the membranous sac that is present around each myofibril and is filled with calcium ions. When muscles are in the resting stage, calcium ions are stored in the sarcoplasmic reticulum.
As the muscle action potential triggers change in voltage-gated calcium ion channels of the sarcoplasmic reticulum, the channels are opened to release the calcium ions in the sarcoplasm. Increased calcium ion levels in sarcoplasm make the muscle fibers to contract.
Removal of acetylcholine from the synaptic cleft ends the production of muscle action potential and calcium ions are moved back from the sarcoplasmic reticulum.
Hence, lower levels of calcium ions are maintained in sarcoplasm when the muscles are in the resting stage.
The nucleus is the control center of a cell in eukaryotes. It is protected by the nuclear membrane. The nucleus holds all of the cell’s genes, which are segments of DNA, found in the chromosomes.
