Why does the opening of K and Cl channels cause a graded hyp

Why does the opening of K+ and Cl- channels cause a graded hyper polarization.?

Solution

During hyperpolarization the membrane potential becomes more negative which is the opposite of depolarization. The efflux of K+ (positively charged potassium ions leaving the cell) and influx of Cl-(negatively charged chloride ions entering the cell) makes the membrane potential negative. Graded hyperpolarization refers to a slight change in the membrane potential proportional to the size of stimulus. Thus opening of K+ allows for efflux of K+ ions and opening of Cl- allows for influx of Cl- ions.