What is transpiration?Why is the epidermis in a leaf covered in a waxy layer?
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Transpiration is a process caused by the evaporation of water from leaves of plants and its corresponding uptake from roots in the soil.\n\nDesert plants and conifers have specially adapted structures, such as needles or thick, fleshy or waxy leaves to reduce transpiration and its effects
681008
Plants respire through stomata... valve-like openings on the underside of their leaves.
955729
A  Epidermis \n\nThe blade consists of an upper and lower epidermis and a spongy layer of tissue, called the mesophyll. Running through the mesophyll is a branching system of veins.\n\nThe epidermis is the leaf blade's skin. It is a thin, usually transparent, colorless layer of cells that covers both the upper and lower surfaces of the blade. The epidermis prevents the leaf from losing excessive amounts of water and protects it against injury.\n\nIn most plants the epidermis is covered with cutin, a waxy substance secreted by the epidermal cells. The layer of cutin, called the cuticle, is responsible for the glossy appearance of some leaves. The cuticle gives the leaf additional protection by slowing down the rate at which water is lost. Generally, the cuticle is thinner on the epidermis on the underside of the leaf than on the upper epidermis, which is exposed to the sun.\n\nIn many kinds of leaves, hairs grow from the epidermis. The soft hairs of plants such as the mullein give the leaves a woolly or feltlike texture. In some plants the epidermal hairs secrete fluids. For example, in geraniums and petunias the hairs secrete a fluid that gives the leaves a clammy texture. The strong-smelling oils of the peppermint and spearmint plants come from epidermal hairs. In other plants, such as the nettle, the epidermal hairs are stiff and contain a poisonous fluid that produces a skin irritation when a person is pricked by them.\n\nB  Guard Cells \n\nScattered throughout the epidermis are pairs of bean-shaped cells, called guard cells. Guard cells contain chloroplasts, which are tiny granules filled with the green pigment chlorophyll. Chlorophyll gives leaves their characteristic green color. Chloroplasts enable leaves to carry on photosynthesis because they are able to absorb carbon dioxide and sunlight, which are required for the food-making process. In response to heat and light, each pair of guard cells pulls apart, and a tiny pore forms between them. The pores, called stomata, open to the outside atmosphere.\n\nWhen the stomata are open, carbon dioxide and oxygen pass either in or out—when carbon dioxide enters, it takes part in photosynthesis, the food-making process that releases oxygen as a waste product. This oxygen passes out of the leaf. At the same time, oxygen also enters the leaf, where it takes part in respiration, a process that forms carbon dioxide as a waste product. This carbon dioxide passes out through the stomata. Water also passes out of the open stomata in the form of a vapor. This process is called transpiration. Generally, there are more stomata on the under surface of a leaf than on the upper surface. This prevents water from evaporating too quickly or in excessive amounts from the leaf's upper side, which is exposed to the sun. Stomata close at night, providing another level of water conservation.\n\nC  Water Pores \n\nIn addition to the stomata, many kinds of leaves have large specialized water pores in their epidermis. These pores, called hydathodes, permit guttation, the process by which a plant loses liquid water. Unlike the stomata, hydathodes remain open all the time.\n\nGuttation takes place only when water is being rapidly absorbed by the roots, such as after a heavy rainfall, and when transpiration slows down, as on cool, humid nights. When these conditions occur together, droplets of water can be seen on the leaf early in the morning before they evaporate in the heat of the day. Unlike dew, which condenses on leaves from water vapor in the air and covers the entire leaf surface, guttation droplets form only on the edges and tips of leaves. Generally, the droplets are noticeable only on the leaves of strawberries and a few other kinds of plants.\n\nD  Mesophyll \n\nThe mesophyll, sandwiched between the upper and lower epidermis, consists of many thin-walled cells that are usually arranged in two layers. The palisade layer is next to the upper epidermis. It consists of cylindrical cells t
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I am highly skeptical of this notion.  However, they affect the moisture content of the air through the transfer of moisture into/out of leaves through holes on the underside called stoma.  Maybe they were referring to heat caused by light shining on the leaves.  This heat would result from absorbance of light.  This heat would radiate off the plant into the air and would warm the air around the plant.  That's all I can hypothesize.
869165
Stomata (singular is stoma) are tiny opening or pores (holes), found mostly on the under-surface(epidermis) of a plant leaf, and used for gas exchange.☺
932165
I would say it is the leaf of a plant or the plant itself.  The leaf gives off oxygen (the waste product) during photosynthesis.\n\nOr: (I grabbed this off Wikipedia)\nphotosynthesis uses water as an electron donor which is oxidized into molecular oxygen by the absorption of a photon by the photosynthetic reaction centre.
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It is the xylem tissue in the xylem vessel that caries water , minerals etc from the roots to the leaves due to a pressure diff in the roots n leaves.\n\nNOT phloem, it is the opposite..it carries food from the leaves to the rest of the plant.
650881
Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. This process occurs in plants and some algae (Kingdom Protista). Plants need only light energy, CO2, and H2O to make sugar. The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis. \n\n Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc. The parts of a typical leaf include the upper and lower epidermis, the mesophyll, the vascular bundle(s) (veins), and the stomates. The upper and lower epidermal cells do not have chloroplasts, thus photosynthesis does not occur there. They serve primarily as protection for the rest of the leaf. The stomates are holes which occur primarily in the lower epidermis and are for air exchange: they let CO2 in and O2 out. The vascular bundles or veins in a leaf are part of the plant's transportation system, moving water and nutrients around the plant as needed. The mesophyll cells have chloroplasts and this is where photosynthesis occurs.The parts of a chloroplast include the outer and inner membranes, intermembrane space, stroma, and thylakoids stacked in grana. The chlorophyll is built into the membranes of the thylakoids. \n\nChlorophyll looks green because it absorbs red and blue light, making these colors unavailable to be seen by our eyes. It is the green light which is NOT absorbed that finally reaches our eyes, making chlorophyll appear green. However, it is the energy from the red and blue light that are absorbed that is, thereby, able to be used to do photosynthesis. The green light we can see is not/cannot be absorbed by the plant, and thus cannot be used to do photosynthesis. \n\nThe overall chemical reaction involved in photosynthesis is: 6CO2 + 6H2O (+ light energy)  C6H12O6 + 6O2. This is the source of the O2 we breathe, and thus, a significant factor in the concerns about deforestation.\n\n  \n\n\nThere are two parts to photosynthesis: \n\nThe light reaction happens in the thylakoid membrane and converts light energy to chemical energy. This chemical reaction must, therefore, take place in the light. Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction. Each of these differently-colored pigments can absorb a slightly different color of light and pass its energy to the central chlorphyll molecule to do photosynthesis. The central part of the chemical structure of a chlorophyll molecule is a porphyrin ring, which consists of several fused rings of carbon and nitrogen with a magnesium ion in the center. \n The energy harvested via the light reaction is stored by forming a chemical called ATP (adenosine triphosphate), a compound used by cells for energy storage. This chemical is made of the nucleotide adenine bonded to a ribose sugar, and that is bonded to three phosphate groups. This molecule is very similar to the building blocks for our DNA. \nThe dark reaction takes place in the stroma within the chloroplast, and converts CO2 to sugar. This reaction doesn't directly need light in order to occur, but it does need the products of the light reaction (ATP and another chemical called NADPH). The dark reaction involves a cycle called the Calvin cycle in which CO2 and energy from ATP are used to form sugar. Actually, notice that the first product of photosynthesis is a three-carbon compound called glyceraldehyde 3-phosphate. Almost immediately, two of these join to form a glucose molecule. \n\nMost plants put CO2 directly into the Calvin cycle. Thus the first stable organic compound formed is the glyceraldehyde 3-phosphate. Since that molecule contains three carbon atoms, these plants are called C3 plants. For all plants, hot summer weather increases the amount of water that evaporates from the plant. Plants lessen the amount of water that evaporates
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Tissues of vascular plant leaves: Leaves are cloaked by a single layer of cells called the epidermis. It protects the leaf from physical damage and pathogens. A transparent, waxy, colorless cuticle coats the epidermis. The stomata ( small holes) are located on the lower epidermis of the leaf. The stomata allow gases and water vapor into and out of the leaf. Each stoma is controlled by two bean shaped guard cells. The palisade mesophyll is a layer of elongated cells containing chloroplasts found just under the upper epidermis. The majority of photosynthesis takes place within this area. Just below the palisade mesophyll is an area of loosely packed parenchyma called the spongy mesophyll. The spongy mesophyll contains air spaces in which gases circulate. The petiole of the leaf connects the blade with the stem. The vascular tissues pass through with the xylem positioned in the top section of the vein while the phloem occupies the lower section.
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stomata are minute openings on the epidermis of leaves which is surrounded by guard cells.the strucutre of a guard cell :\nguard cells generally have thick and non elastic walls towards the pore and thin and elastic walls on the opposite side.\nthe mechanism of stomatal transpiration depends upon the opening and closing of stomata.stomata opens during day time and close at night.the the opening and closing of stomata dependson to how much water is present in the gaurd cells.when there is more water,the guard cells become turgid and the stomata opens and when the amount of water decreases the guard become flaccid and stomata close. \n\nthere are two theories pertaining to this , steward's starch hydrolysis theory and K + pump theory.\nu can surf the net to find out more on this if u want to .
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You don't, it just doesn't evaporate like it would in non-humid conditions.  Its all about the movement of water, and if the air is already very dense with water particles (ie. humidity) then the liquid on your skin is less inclined to enter the air.  But in very dry conditions, the water on your skin evaporates quickly and this cools you down.
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the base of the leaf(pulvinus)on touchin loses its osmoscity,\nthis makes it release water,to saroundin region of higher osmotic pressure\nthis makes the base weak...unable 2 take the weight of the leaf it droops..
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Transpiration, the properties of water, and the vascular tissues help the trees to suck water from the very bottom of the roots to the top of the tree leaves. Transpiration is caused when water is sucked from the root tips of the tree and into the vascular tissue called xylem. Because two of the properties of water state that water is adhesive (they stick to stuff) and cohesive (they stick together), these water molecules stick to the xylem as well as each other, using it's bonds to pull each other up the tree. And when the stomata (the hole on the underside of the leaf) opens for gas exchange, one water molecule at a time evaporates from the leaf, thus pulling the chain up one by one. Hope that helps!
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cactus r xerophytic plants which have the ability to retain water in it.so cactus retains more water and there leaves get modified into spines due to which there is less loss of water from the plant in the atmosphere due to which they can withstand on the extreme condition of water that is where less water is present,and as in desert there is less water so can withstand over there succesfully than to those plants whose leaves are broad and have no cuticle layer.
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Superhydrating....Skin has 3 layers. The bottom/lowest/innermost layer is attached to subcutaneous tissues and does not absorb water. The outermost layer absorbs water and when it "prunes" it swells causing the outermost layer to enlarge and wrinkle, while the innermost layer stays the same.
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In a hypertonic solution the water inside the cell leaves, causing the cell to shrivel.  Since a plant cell has a cell wall, the cytoplasm and plasma membrane will shrink away from the cell wall (called plasmolysis).  This decrease in turgor pressure means the plant will wilt.
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Adaptation, which means that they develop special roots and leaves that make them more prone to survive. Such as some plants have waxy leaves in order to withstand high temepratures and various other conditions. In deserts, some plants have very long roots, which affects if there population is random or very populated.