What is the connection between a circadian rhythm and the biological clock

Larry goes to the doctor complaining that he can't see the right side of the visual field with either eye. where in the visual signal-processing pathway is larry's problem occurring?

In fruit flies, gray bodies (g) are dominant over black bodies (g), and brown pigments (n) are dominant over yellow pigments (n). each individual possesses two alleles for each trait. if a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for both traits, what is the predicted genotype of the offspring.

Why do we perceive objects as retaining their brightness under different lighting levels?