True or false \nthe stomata are found in the spongy layer of leaves.\nthe cells in the palisade layer of a leaf are very important in carring out photosynthesis. \nplease tell me how you got the answers. Thank you so much!
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I will split your question in to two parts viz. 1) Photosynthesis and 2) Stomata; so that you can easily understand it.\n 1) PHOTOSYNTHESIS-: for this function entire middle portion of a leaf contributes, it is called MESOPHYLL in botanical language.(Meso = middle or in between; Phyll = refers to leaf). It is located in between the upper and the lower skin or the epidermis of a leaf (Plural epidermes).\n In most of the leaves the MESOPHYLL is again distinguished it to Upper PALISDE tissue and the Lower SPONGY LAYER.\n Both of them are full of chloroplast and do the function of photosynthesis; but there is a difference.\n The palisade cells are located near the upper epidermis,they are elongated,test tube like in appearence and are placed at right angle to the upper epidermis like upright test tubes.( try to see the meaning of palisade in a good dictionary, it is interesting.). These palisade cells are very closely packed with very little space in between and each of them is literally packed with chloroplasts. That is why a leaf appears greener on its upper surface.Thus, they are ideally located to receive maximum sun light and do maximum photosynthesis.\n\nThe Spongy layer , on the other hand , is located near the lower epidermis of a leaf. The cells are spherical or potato shaped and with lots of intercellular spaces between them. Each cell of this layer contains (comparitively) less or far less number of chloroplasts than the palisade of the same leaf.That is why the same leaf appears pale green on its lower surface.\n This Spongy layer does the function of photosynthesis no doubt ; but it is less in quantity than that of Palisade of the same leaf. This is because it is located rather away from the light source and its main function is to help the leaf in gaseous exchange, that is why there are so many intercellular spaces.( here Photosynthesis is over)... \n\n2) STOMATA (singular stoma) -: These breathing pores are neither IN the palisade layer nor IN the spongy layer. They are a PART of the the two epidermes( upper and lower ).\n If one compares the quantity and the distribution of these stomata of one and the same leaf then they are more on the lower epidermis to help the spongy tissue in gaseous exchange during photosynthesis/respiration.\n On the upper epidermis they are far less in number to reduce or prevent exessive water loss due to transpiration.\nIn many desert plants they are either totally absent from the upper epidermis or located in sunken pits for the same reason.\nI hope you got what you sought. Bye.
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Materials, dissolved (or semi-dissolved?) in water, are moved up and down the plant through the xylem and phloem, such as the previous posts say.  An additional factor to think about is that materials and water also move about because of differences in pressure within the vessels of the plant. At the leaf surface, heat and wind are drying the water that is present.  As this water "dries out" of the plant through the stoma, it creates a vacuum within the vessel it was in.  This, in turn, pulls water up through the plant to replace itself (physics-search for pressure, STP). This whole process is called Transpiration.  Adhesion, thus capillary action, would not be sufficient enough a force to distribute water to the highest part of the plant.
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Check for the optimum texture and pH for the grass.\n\n\nFor the amoeba,i guess it is contractile vacuole.
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Yes sure:\n\nAll plant cells have a cell wall. Young growing cells, some storage cells and the photosynthesizing cells of leaves, all parenchyma cells have only a primary cell wall. The primary cell wall is thin and formed while the cell is undergoing growth. The cell wall surrounds the protoplast [cell membrane and all its contents]. Continuous pressure by the fluids inside the cell forces the cell membrane against the cell wall. Between the primary walls of adjacent cells is the middle lamella which cements the two cells together by means of an adhesive substance called pectin. Mature cells which stop growing lay a secondary wall. \n\nThe primary cell wall\n\nThe primary wall begins to form between cells that are completing cell division. A cell plate forms where a new cell wall will divide the two daughter cells. The cell plate forms from the microtubules. Microtubules may guide materials towards the cell plate which grows to the outside by addition of materials such as pectin. Much of the materials that form the cell plate become the pectin-rich middle lamella between the two cell walls of the daughter cells. As soon as this middle lamella is formed cells release structural material to build the primary cell wall.\n\nThe primary cell wall is thin relative to the secondary cell wall and the entire cell. It is generally 1 to 3μm thick. It consists of 9 to 25% cellulose. Cellulose molecules are unbranched and are bound together by means of hydrogen bonding into long cylindrical fibres called microfibrils [4.5-8.5nm thick]. The microfibril is a polymer of glucose made up of 30-40 pairs of cellulose molecules.\n\nCellulose molecules are arranged in a parallel form and thus microfibrils have an incredible high tensile strength relative to their weight. This orientation allows cells to elongate, the microfibrils slip past each other and are pulled along the axis of the cell. Recent and older microfibrils are laid over each other perpendicularly as threads in cloth.\n\nThe cellulose microfibrils are embedded in a matrix composed of celluloses, pectin and protein. The matrix is composed mainly of hemicelluloses which from a branching network filled with water. The primary cell wall contains 25 to 50% hemicelluloses. Pectic substances make up 10 to 35 % of the cell primary cell wall. Primary cell walls also have 10% protein involved in cell growth and recognition of antigens.  \n\nThe primary cell wall is also adapted for growth. During growth, growth regulating hormones are produced. These soften the primary cell wall and the microfibrils layers [perpendicular] move apart and slide past each other in the wall filled matrix. This takes place with the aid of water which is absorbed by the protoplast thus forcing a pressure against the cell wall. Thus the wall is stretching plastically [irreversible] as the cell grows.\n\nWhen the cell stops growing and cell division is complete, synthesis of growth regulating hormones is stopped and the microfibrils become entangled losing the organized parallel orientation. Therefore the microfibrils can no longer slide past each other and thus the primary cell wall resists further growing by means of the entangled microfibrils which have a high tensile strength. This makes cell walls resistant to swelling if placed in water.\n\nThe primary wall is porous allowing passage of water and materials dissolved in water. The pores are about 3.5 to 5.2nm in diameter compared to the 0.3nm of the diameter of water molecules. The water and other materials can thus pass through the cell wall medium which is called the apoplast.\n\nLeaves and young stems are made up of cells that have mainly primary cell walls. They are rigid when water forces a pressure against the cell wall, but wilt when water is lost and internal pressure decreases. Thus water together with primary cell walls provides a hydrostatic skeleton. \n\nThe secondary wall\n\nIn many plant cells, a primary wall is not enough to withstand the extreme
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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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chlorophyll is needed in the process of photosynthesis. during the photosynthesis oxigen and glucose are produced. when glucose has to be transported from the leaves to the other parts of plants body it is changed into saccharose (sucrose).\nwhen it reaches for example roots and other parts it is transformed into starch. so it is obvious that in the soil there is no sunlight and in the roots there is no chlorophyll, but the process takes place. chlorophyll and sunlight are not needed.
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These answers are taken drectly from the listed link.  \n\nIn animal cells, being in a hypertonic environment results in crenation, where the shape of the cell becomes distorted and wrinkled as water leaves the cell. \n\nPlants thrive in hypotonic environments. Their cells have rigid cell walls that prevent bursting. In fact, the pressure of the cytoplasm against the cell wall keeps the plant from wilting and losing its shape.
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>>>>how is a plant wall made\n\nBy the actions of enzymes that syntehsis celluose from dissolved sugars.\n\n>>>how does a plant get water from the soil to he plant\n\nVia translocation.\n\n>>>what's transpiration?\n\nThe movement of water out of stomata via evaporation.
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these are called the classical "work horses" of plant and aniamal cells respectivly.  Regardless chlorplast is reposnsible the energy conversionin photsysnthesis and mitochondia is used in cell metabolism to provide energy through ATP-ADP energy relationships. Any basic science book would do this and so would a Wikepedia or googlesearch. I woudl suggest you go there to get spsecifics, or try the library in your neighbourhood
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For Plant cells:\n\n1)Parenchyma cells:\n--Primary walls that are rel. thin and flexible, no secondary walls\n-- perform most of the metabolic activity of the cell (photosynthesis etc)\n-- Retain the ability to divide and differentiate\n\n2)Collenchyma cells:\n-- thicker primary walls, no secondary walls\n-- help support young parts of plants\n\n3)Sclerenchyma cells:\n-- thick primary and secondary walls\n-- Can no longer elongate, so occur in parts of the plant that have stopped growing\n-- dead at maturity\n\ntwo catergories: sclereids and fibers\n\n4)Water conducting cells of the xylem\n-- tubular, elongated cells\n--dead at maturity\n\n2 categories:\na) Tracheids: long, thin\nb) Vessel elements: wider, shorter, thinner walled\n\n5) Sugar conducting cells of the phloem\n\n-- Alive at functional maturity:\n* Sieve tube members are the main components of the phloem\n* Companion cells, which facilitate loading sugars
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Abscisic acid causes the stomates to close during times of water stress thus reducing the plant's water loss. It also increases the hydraulic conductivity of the roots.
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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.
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Yes, during photosynthesis, plants and trees take in carbon dioxide and release oxygen into the atmosphere.  For this reason, planting trees is encouraged !
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Non-vascular plants do not have vascular systems to carry water, nutrients, ant the products of photosynthesis throughout the plant. Non-vascular plants include mosses, ferns, hornworts, and liverworts. The mosses, hornworts, and liverworts all transport water by osmosis so they cannot grow very large. This is why they must live so close to water. Ferns have a primitive forrunner of a vascular system, but it is not really a real vascular system because they do not have true roots, and also lack xylem, which is a type of cell that carries water and nutrients up the plant, and phloem, which are cells that can carry water, nutrients, and the products of photosythesis throughout the plant. If you have any more questions, I'll check back here for updates if this was helpfull at all.
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b.root hairs were destroyed.\nthis is because the water is first absorbed by the capillaries in the root hair and then transmitted to the pith.\nthe phloem has no role in absorption.\nhumidity will matter only in the long run as the roots absorb water already in the soil.
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Chloroplast not only have a membrane but they have two an outer and inner. I would go with ribosomes. Everything else has a cell membrane.\nWell this is if you consider the question to ask if the organelle itself has a membrane or the cell in which the orgnelle is contained has a cell membrane.\nI took Ap Bio 2 years ago but I believe the a plant cell also has a cell membrane even though it has a cell wall. The wall keeps them from bursting when they get too much water through osmosis. An animal cell would burst.
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Photosynthesis goes on in the chloroplasts\nphotosynthesis- make their own food by converting light energy into chemical energy