During which of the following does the membrane around the nucleus of the cell begin to disappear??? teleph..?
925721
in prophase only that is 1stphase in mitosis
113839
Endocytosis is when a cell takes outside material inside it.  The cell membrane is a phospholipid bilayer.  This means that that outer and inner surfaces of the memberane like to be with water and the center of the memberane likes to be with oil.    The cell membrane deforms to surround whatever it is trying to bring into the cell.  The membrance then closes around the stuff that it is engulfing.  At this point the cell is still completely surrounded by the membrane; however, there is a new, smaller membrane bound pocket inside of the cell.  That is endocytosis.  If the endocytosis is pH dependent, that means that this cellular process happens in a manner that is related to how acidic or basic the outside enviroment is.\n\nThis question might get a more detailed answer in the biology catagory.
293000
Hard question to answer.  i seem to remember a professor talking on this very subject so i will try and do him justice.\n\n1) surface tension of the phosopholipid bilayer cannot remain bound together once a cell reaches a certain size. another factor is genetic. the genome (depending on the cell type) has a pre determined size. once it is reache a phenominon called apoptosis or cellular suicide is activated bringing a wierd meaning to the welfare of the many outways the welfare of the one. anther aspect is environment.  depending on the cell and the environment it finds itself in, it must compete for for food.  larger cells need more food.  If the food source of the environment is scarce then it wil die as a result of starvation.  in biologic systems immune resppnse may play a significant factor in making the environment too hostile for life.  However lare single cell organisms do exsist.  I will not hand you the answer but I will give you a hint.  Look to Marine life..  good question!
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Cell walls surround the cell outside of the plasma membrane.  When water flows into the cell by osmosis, the cell swells until its membrane builds up pressure against the cell wall.  The cell wall prevents the cell from swelling and bursting in a hypotonic solution.
870168
For a cell without a cell wall, cytokinesis begins with the pinching inward of the cell membrane caused by the action of a ring of special contractile proteins called actin and myosin. The pinching inward forms a deep grove, often called the cleavage furrow. Eventually, the opposite sides of the furrow meet and the cell splits into two new daughter cells. \n\nWhereas cytokinesis in cells lacking a cell wall occurs through a pinching inward, organisms with a cell wall undergo a process through which a so-called cell plate is built from the middle of the cell outward to the membrane. Vesicles from the Golgi bodies flatten and fuse in the center of the cell, forming the cell plate, which elongates toward the cell membrane as more vesicle are added. When the cell plate reaches the cell membrane, the parent cell is effectively separated into two new daughter cells, which then proceed to build a cell wall along the cell plate.
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eukaryotic cell\n\n        a. Bounded by a nuclear membrane having pores connecting it with the endoplasmic reticulum (see Fig. 1 and Fig. 2).\n        b. Contains one or more paired, linear chromosomes (def) composed of deoxyribonucleic acid (DNA) associated with histone proteins (def)).\n        c. Nucleolus (def) present.\n        d. Nuclear body is called a nucleus (def).\n\n          o Electron micrograph of a nucleus courtesy of Dennis Kunkel's Microscopy\n\n    prokaryotic cell \n\n        a. Not bounded by a nuclear membrane (see Fig. 3).\n        b. Usually contains one circular chromosome (def) composed of deoxyribonucleic acid (DNA) associated with histone-like proteins.\n        c. No nucleolus.\n        d. Nuclear body is called a nucleoid (def).
547120
A Bacterium.\n\nCells that lack a membrane-bound nucleus are called prokaryotes (from the Greek meaning before nuclei). These cells have few internal structures that are distinguishable under a microscope. Cells in the monera kingdom such as bacteria and cyanobacteria (also known as blue-green algae) are prokaryotes.
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To be more precise, ribosome is in the cytoplasm which is outside the nucleus.
217907
it's located in the cytoplasm
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Protein along with lipids form a lipoproteinous wall that surrounds the cell which is called plasma-membrane.for details got to below given link:\nhttp://en.wikipedia.org/wiki/Plasma_membrane
935984
For eukaryotes, in the neucleus. For prokaryotes, the cytoplasm because they don't have a nucleus.
880811
I don't have any picutres for you to look at, but I can give you an explanation.\nanimal cells are going to be more rounded, and plant cells are more rectangular.\nRemember: PMAT, these are the phases of mitosis\nProphase-the chromatin begins to condense into chromosomes and the nucleus begins to break down.\nMetaphase-The Chromosomes line up or Meet or "MET" at the cellular equator\nAnaphase- The chromosomes are pulled apart at the centromere\nTelophase- The chromatin decondenses and the neclues reforms\nAlso, the diff. between animal and plant cells....\nAnimal cells have a cleavage furrowl like a figure-8.\nPlant cells build a cell plate in between the separated chromosomes\nMitosis results in two daughter chromosomes.
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Definitely b...\nDuring Interphase, there are 3 subphases - G1, S, and G2.  G1 is for growth of the cell, S is for synthesis of an extra set of chromosomes (amount of DNA in cells), and G2 is for preparation for the rest of cell division.  After interphase is prophase (nuclear membrane dissolves and DNA bundles up), then metaphase (DNA lines up on the center of the cell), anaphase (DNA separates towards poles), and telophase (Cell divides into two cells).  I hope this helps!\n\nAnswer: b. between the G1 and G2 phases of the cell cycle
120491
As the name implies it is outer thin layer of a LIVING cell.In plant cells in addition to the cell membrane there is a cell wall,either of cellulose or lignin,which is the external most, protective covering.The cell membrane controls the entry and exits of molecules in side the LIVING cell from out side.The cell wall provides protection and gives shape to the cell, both living as well as dead.What we call wood is a collection of billions of dead plants cells that have strong lignified walls.\nAnimal cells lack a proper cell wall.\nOne can easily see a cell membrane with naked eyes. Take a hard boiled poultry egg. Gently crack and remove the outer SHELL which  is of calcium carbonate.Just on its inner side and coverig the WHITE of the egg ( which is now hard and firm) one is sure to find an extermely thin membrane.That is the CELL MEMBRANE! One can see it in afresh egg as well but for a first timer boiled egg is easier. Cell membrane is also called PLASMA MEMBRANE, as it forms the outer limits of the living cytoplasm of a cell.\nThe information above will make one believe that an egg is a cell. Yes it is true in all its aspects. It IS a CELL and since it has to survive out side the animal body, it is provided with a shell which is not a part of the cell.Poultry egg, or for that matter any egg is a cell. An ostrich's egg is the largest cell of all!.
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Cytokinesis is the final stage of cell reproduction; it is the division of the cytoplasm into approximately equal halves, resulting in a roughly equal distribution of organelles in each of the daughter cells. Cytokinesis usually begins in telophase. We will discuss cytokinesis separately for organisms which do not have a cell wall (mostly heterotrophs) and those which do have a cell wall (generally autotrophs).\n\nFor a cell without a cell wall, cytokinesis begins with the pinching inward of the cell membrane caused by the action of a ring of special contractile proteins called actin and myosin. The pinching inward forms a deep grove, often called the cleavage furrow. Eventually, the opposite sides of the furrow meet and the cell splits into two new daughter cells.\n\nWhereas cytokinesis in cells lacking a cell wall occurs through a pinching inward, organisms with a cell wall undergo a process through which a so-called cell plate is built from the middle of the cell outward to the membrane. Vesicles from the Golgi bodies flatten and fuse in the center of the cell, forming the cell plate, which elongates toward the cell membrane as more vesicle are added. When the cell plate reaches the cell membrane, the parent cell is effectively separated into two new daughter cells, which then proceed to build a cell wall along the cell plate.
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Okay this is a bit of a complicated question, but i'll do my best, in short these are really very different things.\n\nFirst cell membranes are found in all cells (animal, plant, fungi etc.) they are made up of lipids, generally as a bilayer.  take the membrane from around the outside of a eukaryotic cell, its formed from phospolipids - these molecules have a hydrophilic head [ie will disolve in water/ has a charge] (the phosphate bit) and a hydrophobic tail (the lipid (fat) bit). The hydrophobic bits stick together and the hydrophilic bits are open to the solution on each side (search "lipid bilayer" with yahoo! Images if you want a diagram:-) ).  The outer cell membrane is forming a barrier between the inside and outside of the cell, alowing the cell to control the movment of molecules into and out of itself.  There are a lot of other membranes in the cell apart from the outher cell membrane, the endoplasmic reticulum for example is basicly made up of membrane.\n\nThe cell wall on the other hand isn't present in all cells (we humans (along with all other animals) don't get one). The cell wall is present on the extracellular side of the outer cell membrane.  it is hard and ridgid (unlike the membrane that is fluid) it is made up of lond polymers, and serves to protect the cell.  Plant cell walls are made up of mainly cellulose (in fact when you look at a peice of wood all you are really seeing is the leftover cell walls, and the rest of the cell has long gone).  Fungi also have cell walls but this time not made of cellulose but instead made of chitin, the cell wall still serves the same role however.\n\nIn short the membrane lets the cell control what goes in and out,  and the cell wall provides rigidity.  Membranes are made of lipids (fats) and cell walls of long polemers like chitin and cellulose.\n\nI hope this helps to answer your question, and look for some diagrams - it will make it a lot easier.
764570
The semipermeable membrane that encloses the cytoplasm of a cell.