How do cells move potassium ions against a concentration gradient, from a lower concentration to a higher one

How does a gymnosperm prevent itself from pollinating the same tree

Does anyone know what a poms statement is for biology? i don't know what it is and i have an assignment on it tomorrow, will award the best answer a brainliest!

Some tools have graduations to show multiple measurements. for example, a ruler may have graduations for both millimeters and centimeters. when measuring the length of an earthworm, which graduations would allow for the most accurate measurement? millimeters centimeters decimeters meters