A good way to understand the function of a certain tissue or organ is to imagine what would happen if it suddenly stopped functioning. Suppose you could magically remove each of the structures listed below from an apple tree, leaving all of its other tissues intact. In each case, what would happen to the tree?

-Apical meristems - The tree would be unable to growth in length, (e.g. branch tips and root tips would stop growing). It could still grow in width.

-Stomata - No gas exchange would occur in the leaves; eventually photosynthesis and respiration would both stop.

-Parenchyma cells - No photosynthesis could occur in the leaves; no protein would be stored in the apples.

-Root hairs - The tree would have much less surface area to take up water and nutrients from the soil. Its shoot system would probably die.

-Cuticle - The leaves would lose a large amount of water.

-Cork - The trunk would lose its major defense against insects and pathogens, and would also start losing a large amount of water.

-Vessel elements - The tree would be unable to transport water up the trunk.

-Sieve plates - The tree would no longer be able to transport materials through the phloem. Sap (containing carbohydrates made by the leaves) would cease to flow down the trunk, and the roots would soon become starved of fuel.

-Of all of these structures, the only one that would not kill the tree is probably the loss of apical meristems. Loss of apical meristems simply prevents growth, but doesn't interfere with key physiological processes. (In fact, pruning of fruit trees is exactly this - removal of the apical meristems.)

Explanation:

The plant body is organized and constructed in a distinctive way

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.