Some regions of a polypeptide may coil or fold back on themselves. this is called and the coils or folds are held in place by
a. tertiary structure covalent bonds
b. primary structure covalent bonds
c. tertiary structure hydrogen bonds
d. secondary structure hydrogen bonds
e. secondary structure peptide bonds

Chalk is an ionic compound. which is a property of all ionic compounds that makes chalkboard? particularly useful for writing on a a high melting point hardness and brittleness inability to dissolve in water a multicolored appearance

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

The is an estimate of the fewest number of organisms a population needs to avoid extinction. this measurement will most if the number of offspring each female in the population produces increases. if the population's this measurement will most likely increase. 1 population density, minimum viable population, carrying capacity 2 decrease, be unaffected, increase 3 death rate increase, dead rate decrease