Disorders, such as sickle cell anemia, are the result of mutations of the a) brain. b) chromosomes. c) heart. d) nucleolus

the concept of nucleosome occupancy, which reflects the fraction of cells from the population in which a given region of dna is occupied by a histone octamer

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.