Which two organelles are responsible for providing the plant cell with energy?

When analyzing tree rings, what do scientists assume a thin ring indicates?

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

Which of these is a provisioning service people get from the ocean