What are "null" cells?
435517
lymphocytes lacking typical markers of t or b-cells capable of lysing a variety of tumor or virus infected cells without obvious antigenic stimulation also effect antibody dependent cell cytotoxicity,carry in humans cd16 markers.
23074
Mesenchymal cells, also known as mesenchymal stem cells or marrow stromal cells (MSC), are stem cells.
791878
They start to elongate and they move around to different positions in the embryo.  Lack of movement of certain clusters of cells usually causes non-development of tissues, organs, or whole systems.
210243
in reality - null\nin math it allows us to put a placeholder between positive and negative numbers. It also allows a higher understanding of how math really works.
1038177
prokaryotic cells are the ONLY cells on that list that have no nucleus or organelles....\n\n...someone hasn't been paying very much attention in class....
775243
http://www.cellsalive.com/index.htm\n\nThis site does it better than I do. Hope this helps! :) :) :) :) :) :) :) :)
741835
All human beings start their lives from a single cell, called the zygote, which is formed after fertilization. The zygote divides and forms two cells; each of those cells divides again, and so on. Pretty soon, about five days after conception, there is hollow ball of about 150 cells called the blastocyst. The blastocyst is smaller than a grain of sand and contains two types of cells, the trophoblast and the inner cell mass. Embryonic stem cells are the cells that make up the inner cell mass. As embryonic stem cells can form all cell types in an adult, they are referred to as pluripotent stem cells.\n\nStem cells can also be found in very small numbers in various tissues in the adult body. For example, bone marrow stem cells are found in the marrow of the bone and they give rise to all specialized blood cell types. Adult stem cells are typically programmed to form different cell types of their own tissue; they are called multipotent stem cells. Adult stem cells have not yet been identified in all vital organs. In some tissues like the brain, although stem cells exist, they are not very active, and thus do not readily respond to cell injury or damage. Scientists are now also exploring ways in which they can induce the stem cells already present to grow and make the right cell types to replace the damaged ones. \n\nStem cells can also be obtained from sources like the umbilical cord of a newborn baby. This is an accessible source of stem cells, compared to adult tissues like the brain and bone marrow. Although scientists can grow these cells in culture dishes, they can do so only for a limited time. Recently, scientists have discovered the existence of stem cells in baby teeth and in amniotic fluid-the "water bath" that surrounds an unborn baby- and these cells may also have the potential to form multiple cell types. Research to characterize and study these cells is very promising but at a very early stage.
312559
animal cells don't have a cell wall
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Here is what i could fined but i was unable to find anything on the leaf eperdemal cells.\n\nA red blood cell is - a cell in the blood of vertebrates that transports oxygen and carbon dioxide to and from the tissues\n\nprotozoans - Any of a large group of single-celled, usually microscopic, eukaryotic organisms, such as amoebas, ciliates, flagellates, and sporozoans.\n\nPhloem - the part of a vascular bundle consisting of sieve tubes, companion cells, parenchyma, and fibers and forming the food-conducting tissue of a plant. \n\nMuscle cells - an elongated contractile cell that forms the muscles of the body\n\n Xylem -a compound tissue in vascular plants that helps provide support and that conducts water and nutrients upward from the roots, consisting of tracheids, vessels, parenchyma cells, and woody fibers.
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If you would like to learn about cells, then you will love this site for the rest of your life:\n\nhttp://www.cellsalive.com/
44587
That depends on the type of cell and its function.
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if ur talking about cells... i think it is organelles...not sure
90731
Yes.  You should know that if you've looked at them under a light microscope.  This applies for pretty much all cells of the same type, since cells can be neither too big nor too small.  If they're too big, then information has a hard time travelling through the large amounts of space and cytoplasm, and the cell can't function.  If they're too small... not everything fits.
1065252
There are two types of cells. Rod & cone cells. Rod cells are responsible for black & white vision, cone cells for color vision. at the yellow spot, there are only cone cells, at the other areas of the retina, there are rod cells. At the blind spot, there is neither.
191035
all cells are composed of atoms in the nucleous.  All cells have a cell wall/cell membrane, cytoplasm/protoplasm.\ngolgi bodies\n\n\nYou can't have a cell without these things
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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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You have to put this if condition\n\ngoto b1 cell and put this formula =if(a1="ON",1,if(a1="OFF",0,"EMPTY"))\n\nif you can't read full formula please move your mouse pointer over it. then it will be displayed full.\n\nso when you put ON in a1 cell, that will display 1 and when you put OFF b1 cell will display   0   if a1 cell remains empty, then b1 will display "EMPTY"