Different cell types and tissues express different sets of genes; for example, some genes are expressed primarily in the heart, others primarily in the brain, and still others primarily in the liver. This is possible because all of these cell types have . a. different sequence variants that control gene expression
b. different ordering of genes on chromosomes
c. different histone and DNA modifications
d. different sets of genes

Why do bacteria thrive even in hostile environments

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

Building glycogen from glucose molecules is an example of what