This image shows the various forces acting on a block of rock situated on a rock slope. what does arrow 4 represent?

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?

Environmental differences within ecosystems are generally caused by

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations