There are inner part of the stem and outer part of the stem; in a plant the inner part supports the movement of the water and nutrients. You stop the flow of the vital elements of plant growth when you snap the stem and this is the reason why the plant die due to starvation of the nutrients.
This has to do with SURFACE TO VOLUME RATIO. For a typical small cell, its surface area to the volume ratio get smaller as the cell grows. This implies that, if the cell grows beyond a certain limit, then the amount of nutrients that entered the cell will be limited, that is , nutrients will not be able to migrate into the cell as needed. To avoid this, the cell has to divide to reduce its surface to volume ratio.<span />
A membrane bounded organelle whose main function is to undergo protein synthesis would be the ribosomes. These can be embedded in the endoplasmic reticulum or be freely floating in the cytoplasmic region of the cell.
A lava flow it the spread of lava that pours out of a volcano
