Acell has a membrane potential of -100 mv (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. which best describes a mechanism by which ca²⁺ enters this cell?
a. facilitated diffusion of ca²⁺ into the cell down its electrochemical gradient
b. movement of ca²⁺ into the cell through an ion channel down its concentration gradient
c. passive diffusion of ca²⁺ into the cell down its electrochemical gradient
d. cotransport of ca²⁺ into the cell with cl⁻
e. movement of ca²⁺ into the cell through a carrier protein down its electrical gradient

b. movement of Ca²⁺ into the cell through an ion channel down its concentration gradient.

Explanation:

Ca²⁺ ions move from the outside to the inside of the cell through an ion channel because of the difference in concentration at both sides of the cellular membrane. A Ca²⁺channel can be open or close if it is closed a change in the membrane potential opens it to let the Ca²⁺ ions inside the cell.

the answer is d. exposing corruption in the church

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.