Measuring photosynthesis via the production of oxygen. Oxygen can be measured by counting bubbles evolved from pondweed, or by using the Audus apparatus to measure the amount of gas evolved over a period of time.
The inferior vena cava brings deoxygenated blood back into the heart from the lower body. For comparison, the part that directs deoxygenated blood from the upper body is the superior vena cava.
Answer is for the earths core to cool enough for convection to stop, then the plates would have no convection current to move them.
Explanation: If the Earth's core were to cool down, the convection currents in the mantle would stop moving. Since the convection currents drive the plates, they would stop moving.
Answer:
out of the cell
bc water goes towards salt