An alloy is made by mixing 180cmº iron metal of density 2000kg/m3 with 120cm of lead meal of density 4g/cm3 Calculate the density of the alloy.

answer: the correct answer for the fill in the blank is rods.

rods are the specialized photoreceptor cells that are present in the retina of human eye. they are responsible for vision in the night time ( also called scotopic vision). they have very low visual acuity and color distinguishing ability.

as they are responsible for vision in night time, therefore they are found predominantly in the nocturnal animals.