Many cacti do not have leaves but rather have oversized stems.. what role of leaves is therefore taken on by the stems of cacti

a. they produce food by photosynthesis

b. they absorb water and nutrients from the soil

c. they transport materials throughout the plant

d. they store excess water

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

Which type of bond forms between water moleculesstrong bondhydrogen bondcovalent bondpolar bond

Which of the following is an effect of the uneven heating of the earth by the sun? a sea breeze a land breeze a convection current all of the above