The leaves of the three different plants (mesophyte, hydrophyte and xerophyte) have all adapted in different ways in order for the plant to flourish in its environment. The leaves of an oak tree are big and there are lots of them they grow at the top of the tree in order to absorb enough sunlight to carry out photosynthesis. The leaves of an oak tree often fall of in winter, as this will conserve water and energy as often in winter not enough sunlight will be available to these plants so photosynthesis would not occur any way (1). This contrasts to the leaves of a water Lilly which are broad and lay flat on the surface of the water they are also well developed air chambers to give the leaves bouncy as the leaves need to float (2). The leaves are broad in order to increase the surface area for sunlight to be absorbed the leaves inter cellular tissue are also arranged to share gases from the exposed part of the leaf to the summered bottom part of the leaf. The leaves of the water Lilly and Oak tree are able to be big as water loss is not such a big problem, this is because water Lilly live in a environment where there is an abundance of water and Oak trees live in an environment where there is rarely a shortage of water. The leaves of the Water Lilly and oak tree contrast to the leaves of the barrel cactus where in fact the leaves have been reduced to spines, this is because if the plant did have leaves there would be to much surface area for transpiration to occur and water loss is a problem in the barrel cactus as it lives in an environment where it rarely rains so its important for the plant to conserve water. So by reducing it leaves to spines there is a smaller surface area for transpiration (3). One thing all three of these plants have in common is they all have a waxy cuticle, the oak tree has a waxy cuticle on the upper side of the leaf to prevent water loss as it traps water within the plant(4), the waxy cuticle of the barrel cactus has a similar function but its located all over the plants stem and is much thicker, this is because the stomata are located on the stem of the barrel cactus and water conservation is extremely important for the barrel cactus. The thick waxy cuticle of the barrel cactus traps moisture with in the plant so water balance can be controlled as unlike the Water Lilly who lives in abundance of water the barrel cactus needs to conserve as much water possible due to the water shortage in its given environment (6). The waxy cuticle of the water Lilly has a slightly different role compared to the oak tree and barrel cactus it is located on the top of the leaf like the oak tree but its job is to keep water away from the stomata as if water was to sit on the top of the exposed leaves the plant would sink due to the water weight but it would also stop gas exchange and transpiration. Because the Water Lilly live in an aquatic environment water loss is not a problem but actually helps the plant keep a balance of water as if the plant contained too much water then to would drown (5). Although all three plants have a waxy cuticle its function is slightly different for each plant as in the barrel cactus it'd function is to slow down water loss as water is scarce but in the water Lilly its function is to protect the stomata so water can be lost and the plant does not drown as water loss is not a problem as the Water Lilly lives in abundance of it. The leaves of all these plants have adapted in different ways to control water levels with in the plant, the leaves of the Water Lilly Oak Tree are much bigger than the leaves of barrel cactus, which have been reduced to spines. All of these plants need water in order to carry out processes such as photosynthesis as water is a raw material in this process. They also need water in order for their cells to stay turgid as plants do not have skeletons like animals do so they relay on their vacuoles being fill of water to keep the upright structure of the plant, this is important as the plant needs to stay upright in order for them to absorb sunlight. This is why it is so important for water balance to be controlled in the plant, as all these plants will fail to survive if water balance in the plant was not controlled.
(1)http://www.ehow.com/info_8013032_do-oak-trees-lose-leaves.html
(2) http://www.botgard.ucla.edu/html/botanytextbooks/lifeforms/aquaticplants/fulltextonly.html
(3)http://www.ehow.com/info_11384273_adaptations-barrel-cactus.html
(4)http://www.edurite.com/kbase/adaptations-of-mesophytes
(5)http://www.thestudentroom.co.uk/wiki/Revision:Xerophytes_and_Hydrophytes
(6) http://www.conservancy.co.uk/learn/downloads/fieldtrips/xerophytes.pdf
These sights may be used in more than one place but the numbers show where the information has obviously used
how why
(1)http://www.ehow.com/info_8013032_do-oak-trees-lose-leaves.html
(2) http://www.botgard.ucla.edu/html/botanytextbooks/lifeforms/aquaticplants/fulltextonly.html
(3)http://www.ehow.com/info_11384273_adaptations-barrel-cactus.html
(4)http://www.edurite.com/kbase/adaptations-of-mesophytes
(5)http://www.thestudentroom.co.uk/wiki/Revision:Xerophytes_and_Hydrophytes
(6) http://www.conservancy.co.uk/learn/downloads/fieldtrips/xerophytes.pdf
These sights may be used in more than one place but the numbers show where the information has obviously used
how why