What happens when the livestock grazing on rangelands remove ALL or
MOST of the grass cover?
A. it depends on the species of grass
B. nothing - the grass just grows back
C. soil erosion from wind and water occurs much quicker
D. the less rain can reach the soil

Which of the following examples can cause gene flow between populations? a. an increase in predators to a population of zebra b. a volcanic eruption that kills half of a population of mice c. bird droppings that contain seeds from a different location d. a person that sprays a toxin on a group of mosquitoes

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

What are the two main phases of a cell cycle