Which interaction is most likely to result in the most competitive among the organisms?
1. Sagebrush and cacti obtain light in the desert.
2. Producers and scavengers eat deer carcasses.
3. Grasshoppers and caterpillars eat oak leaves.
4. Lions and vultures eat the remains left after a lion kill.

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

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

If an organ has six haploid chromosomes, how many chromosomes are present. 6 12