Why does a plant cell have a cell wall & membrane and a animal cell only has a membrane?
828421
Animals are supported by a skeleton, made of bone.  Plants don't have skeletons, they use a cell wall to give them support.  Such walls wound make movement impractical.
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CELL MEMBRANE IS THE BOUNDARY BETWEEN IT'S CELL AND IT ENVIRONMENT
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The relative rigidity of the cell wall renders plants sedentary, unlike animals, whose lack of this type of structure allows their cells more flexibility, which is necessary for locomotion. The plant cell wall serves a variety of functions. Along with protecting the intracellular contents, the structure bestows rigidity to the plant, provides a porous medium for the circulation and distribution of water, minerals, and other nutrients, and houses specialized molecules that regulate growth and protect the plant from disease.(plants do not have an immunity system, and cell wall is a good barrier)
967427
Some pros\n\nCells with a cell wall are stronger \nCells can withtsand far greater degrees of positive osmotic pressure (higher concentrations of water outside of the cell).\nWhen cells die they can still serve a purpose within the organism by contributing to structural rigidity or fluid transport (e.g. xylum in plants)\n\nSome cons\nCells with cell walls are limited in size by the size of the cell wall\nIn situations of high negative osmotic pressure the cell membrane can detatch from the cell wall and is often ruptured, killing the cell\nCells with cell walls are very rarely able to move unless they have specialist attatchments like flagella
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animal cell\ncell membrane - controls what moves in and out of the cell\ncytoplasm - the jelly like substance the organelles sit in\nnucleus - controls the actions of the cell\nlysosome - structure with digestive enzymes that break down wornout cells and debris\nvacuole - stores food, water, and wastes\nnuclear membrane/envelope - controls what moves in and out of the nucleus\nribosomes - synthesize and produce proteins\nendoplasmic reticulum - synthesizes materials and transports them to other parts of the cell\ngolgi body - packages and modifies materials and sends them to other cells\nchromatin - genetic information that tells the what to do\nnucleolus - knot of chromatin that produces ribosomes\nmitochondria - produces energy for cell\n\nPlant cell ( added on )\ncell wall - a rigid layer that gives shape and supports the cell\nchloroplasts - absorbs sunlight needed for photosynthesis
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The cell membrane is a lipid bilayer made from phospholipids.  As a lipid, it is permeable to other lipids (e.g. steroid hormones) but not to polar molecules (e.g. potassium or glucose).  Polar molecules require various types of membrane proteins (e.g. potassium channels) or endocytosis (glucose) for absorption into the cell.  \n\nHope this is helpful for you.  Best wishes and good luck.
319932
all plant life have rectangle shaped cells
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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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plant cells form a disk during the final splitting phase, while animal membranes constrict.  Also, it is easier to see earlier in animals, and animals have centrioles, plants dont.  thats all my textbook says.  the phases and everything are the same, though.
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Yes, guard cells are the only cells in the cell wall that conating chloroplasts. the reason for this been they help to control the opening and the closing of the stomata (the ope that allows gaseous exchange of CO2 and O2.\nDuring the day there is light so the plants can Photosynthesis as CO2 is used up during photosynthesis theCO2 levels in the guard cells falls. This causes water and  salts to be draged into the guard cells and the guard  cells swell up, thus opening the stomata pore .\nAt night CO2 levels are high as photosynthesis cant take place due tothe absence of light and the CO 2 levels rises so water and salt leave the guard cells and they shrink and thus close the stomata pore.
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animal cells are smaller and more numrous
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An animal cell is a form of eukaryotic cell which make up many tissues in animals. The animal cell is distinct from other eukaryotes, most notably plant cells, as they lack cell walls and chloroplasts, and they have smaller vacuoles. Due to the lack of a rigid cell wall, animal cells appear to be circular (though are often deformed by surrounding cells) under microscopes - in three dimensions the cells are normally spherical.
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Formation of a cell wall is a characteristic feature of all plant cells.Its formation in angiosperms does not differ much from its formation in other plants cells.\n After the nuclear division is over (end of karyokinesis)only then the division of cytoplasm(cytokinesis) begins.\n A number of microtubules are laid across the original cell, equidistant from the two recently formed daughter nuclei. They fuse to form middle lamella.This is the first dividing boundery between the two cells. Deposition of cellulose now begins on this middle lamella from either side and the wall formation is completed. Thus, a cell wall in plant cells is by and large made up of a complex carbohydrate called cellulose and in between the two layers of cellulose there is a layer called middle lamella.It is like butter sandwich. Just as the layer of butter holds the two slices of bread together or just as the layer of cement holds two adjecent bricks together and forms a wall; like wise the middle lamella holds the cells together and helps to form a tissue.
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Water equalizes the pressure between the outside and the inside of the cell wall, so it doesn't become damaged.  It also is the transport medium for nutrients coming in, and waste exiting.
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In plant cells Cell Plates appear after division of nuclease which divide it in to two equal daughter cell, while in animal cell after nuclease division cell membrane receive external pressure which devoid Cell in to two equal cells.
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They are eukaryotic, multicellular, and in the kingdom Animalia. They come from mammals (you and me) and so that means they have an membrane enclosed nucleus, as opposed to prokaryotic cells that don't have a nucleus.  They are multicellular b/c all animals are.  And the kindom Animalia applies cheek cells as well. :)
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prokaryotic cells are not bounded by membranes while eukaryotic cells are bounded by membranes.