Only humans have cells that are specialized to do special jobs. true or false?
553375
False. All creatures, from worms to humans, have specialized cells.
180604
No, the human body is a very large collection of atoms, the cells are made up of all sorts of things taht each could be divided into smaller things and that on the other hand maybe can bedivided into smaller things until you find that all that is left is atoms.
169320
I think he was talking about technologies where they can grow human parts on rats and such using stem cells...like grow ears and human skin on host animals that can be harvested for transplants and such.  Not sure how this is too different from doing transplants with pig hearts and such....
969513
Early embryonic cells are meristematic ("stem") and not specialized to do anything in particular. As the embryo develops these cells specialize to perform various specific or specialized functions. Examples: Muscle cells-contraction/movement ; nerve cells-carry impulses ; epidermal cells-covering ; gland cells-secretions, etc.\n  There are several theories as to how these unspecialized cells specialize (or differentiate).
67593
Stem cells are remarkable in that they can develop into all sorts of other specialised cells.\nOnce a cell is specialised it cannot change.\nStem cells therefore have the potential to replace cells that have been damaged by disease or injury.\n\nLook here:
221242
Parenchyma cells are the most abundant.  They are undifferentiated and fill the spaces between more specialized tissues, and are involved in wound healing.
404721
It depends on the organism.  Humans are just built that way.  Other species like frogs continually generate oocytes (the egg precursor).  What happens in humans is usually not an absolute truth for other animals.  Some animals are asexual (no sperm needed).  All sorts of variations on the theme exists.
288876
Yes. They are probably microbes or even smaller nanobacteria. \n\nI have seen the work of Dr. Robert Folk at the University of Texas, who examined the Martian meteorites found in Antarctica and found possible fossil evidence of nanobacteria. Many biologists are not convinced that nanobacteria (which are measured in nanometers) even exist and argue that they are too small to contain the functions of a living cell. The topic remains controversial.   \nHere is a page discussing the biological controversy (there are some geological controversies as well):\nhttp://serc.carleton.edu/microbelife/topics/nanobes/index.html\n\nHere is the NASA page describing the findings:\nhttp://nssdc.gsfc.nasa.gov/planetary/marslife.html
637931
Depends on what type of life you mean. Human life, No. Humans only exist on earth and other space stations where technology has propelled mankind to.
695452
each organ performs a specific function for the organism, just like organelles perform a specific function for the cell.  hence organelle, "little organ."
739107
NO! Every multicellular eukaryotic organism on earth has mitosis.
695489
http://en.wikipedia.org/wiki/Human_cells
1032620
Many animals have abilities that would be considered super to humans.  Things like regeneration,  flight, and ability to tolerate different temperatures.  when we know more about genetic es in humans there maybe a time that we could adapt these abilities to humans.  It is certainly a consideration for living on other planets.  \n\nBut it is possible to use your muscles more efficiently if the right chemicals were present in your body.  People during times of stress have shown increase abilities to to incredible feats of strength.  \n\nAlso some people have uncanny abilities to see and hear things that others do not normally hear or see.  Same with the brain some brains are just wired to me more efficient with things like problem solving, ability to remain calm in stressful times.  Abilities to slow your heart rate to a very low level has been done by some monks that are very disciplined in meditations.
412213
Stem cells originate from embryos which are a few days old. There are very strict guidelines regarding the harvest of stem cells, and they cannot be harvested from human beings beyond the embryo stage. They certainly do not come from the human brain.
656156
False, its the other way round.\nSingle celled orgarnisms have only one cell. this cell has different components that help it become multi-funtional. this means that its single cell are not specialised. for example. an Amoeaba which is a single celled organism has a nuclei which it uses for its metabolic processes, its mitochondria for energy, its cell wall for movement. so this one cell of an amoeba can perform different functions.\n\nmulti cellular ogarnisms have different cells that have been specialised for different purposes. e.g respiratory cells are for metabolic processes, growth cells are for growth, digestive cells are for digestion. \n\nthe digestive cells in a multicellular organisn come together to form digestive tissues. the digestive tissues will come together to form a digestive organ, different digestive organs will form the digestive system. different systems form the body.\n\nthanks. chaoo
594017
Being single celled. They have some of the most complex cells because their cells have to do all the work - as opposed to multicellular animals which have division of labour.
997050
Sure there are. There are many as-yet undiscovered species within out own world. Remember also, that we are but one of thousands of "species" living on the earth. While not provable at this point, given the vastness of our universe, it is likely that there are other forms of life elsewhere. I'd not imagine "little green men" as much as simple-cellular forms.