Some hatchetfish can produce bright bioluminescence on their undersides, while others can only produce weak light. If a population of hatchetfish lives in water that gets cloudy due to volcanic eruption, which prediction is accurate?

A
Both fish groups will survive and reproduce better.
B
The weak-light hatchetfish will survive better than the bright-light hatchetfish.
C
The bright-light hatchetfish will survive better than the weak-light hatchetfish.
D
There will be no difference in survival between the two groups of fish.

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

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 skeletal system is represented by the shaded portion of the skeleton? spongy skeleton compact skeleton axial skeleton appendicular skeleton