Neofronteras "The world Volvox - Home -
One of the microscopic forms most beautiful and fascinating life that can be found in a drop of water is the Volvox. bergstrom There, under the scrutiny of the lens of the microscope, Volvox, spherical, like a precious photosynthetic green planet, a microcosm of life. We will see in the end that this metaphor remains beyond what we believe. The Volvox related species distributed worldwide. It is commonly found in lakes or deep freshwater ponds. Some relatives are unicellular algae, while some form colonies that grow to 50,000 algal cells. As we will see their cells are specialized by function and are not simply together. Have some level of "social" bergstrom organization among them. Volvox is a typical colony of about 2000 algae cells embedded in a gelatinous all area of glycoproteins and some cases are joined together by cytoplasmic filaments. Flagellated cells surface is coordinated so that the colony can be moved in the water. Usually does to the light, because it has very sensitive cells located predominantly bergstrom in the "northern hemisphere" of this "microplaneta". Each cell measures about 5 microns, but the colony can have half a millimeter or even reach 2 mm or more in some species. The largest can be seen with the naked eye. Volvox cells are specialized, or form part of reproduction or locomotion, bergstrom but do not have both functions bergstrom simultaneously. It's reproductive system is most fascinating, has asexual and sexual reproduction simultaneously. Within each of these areas grow within other areas are further colonies are called gonads Volvox. The gonads arise from cells in the "Ecuador" of the colony, but with the disadvantage of having flagella pointing inside of the sphere. To fix this problem further small colonies have to turn around like a sock when they are still small and are within their parent colony. Once they reach maturity mother colony ruptures releasing the new colonies that have grown inside, and that in turn lead granddaughters and colonies inside. Flagellated bergstrom surface cells. Photo: Wim van Egmond.
There are male and female colonies with specialized cells that form in the Ecuador or eggs or sperm. There are also hermaphroditic species, bergstrom but the production of sperm and eggs is not synchronized to avoid self-fertilization. The fertilized eggs, once developed, will form a new colony later, this time with genes from two individuals through this sexual reproduction. The Volvox may even have indoor inhabitants of other unrelated species. Specifically there is a kind of rotifer (Proales parasite) that can be introduced into living cells and algae (a parasite). The rotifer can detect if the colony is still. If this happens quickly perform a hole in the surface and escape. As you can see, the Volvox is a good model of organization intermediate stage between unicellular bergstrom organisms and more complex multicellular organisms. If you want to know how cooperation between individual bergstrom cells appeared to form a more complex system, the Volvox could provide clues. Cells of this kind are linked by Volvox cytoplasmic fibers. Photo: Wim van Egmond.
All macroscopic organisms have a unicellular ancestor and each group of creatures that now we had to suffer in the distant past a transition of this type. That changes in the cooperation and conflicts between individual cells led somehow and in some cases, at a resolution of these conflicts and the formation of colonies that would later evolve into multicellular organisms fully believed. This would have occurred sometime over 600 million years ago in the Neoproterozoic, but may have tried more times since. Until recently it was believed that the first Volvox appeared only 50 million years ago, but according to a new study, for which are used the most modern genetic techniques, these colonies have appeared about 200 million years ago during the Triassic. bergstrom At that time the world was populated by primitive dinosaurs, reptiles mamÃferoideos, tree ferns, ginkgo and some conifer. There were no flowers, no pollinating insects, no grass, no ruminants. According to Matthew D. Herron at the University of Arizona in Tucson, one of the authors of the study, Volvox cells went from being independent to being a colony in only 35 million years a parp
One of the microscopic forms most beautiful and fascinating life that can be found in a drop of water is the Volvox. bergstrom There, under the scrutiny of the lens of the microscope, Volvox, spherical, like a precious photosynthetic green planet, a microcosm of life. We will see in the end that this metaphor remains beyond what we believe. The Volvox related species distributed worldwide. It is commonly found in lakes or deep freshwater ponds. Some relatives are unicellular algae, while some form colonies that grow to 50,000 algal cells. As we will see their cells are specialized by function and are not simply together. Have some level of "social" bergstrom organization among them. Volvox is a typical colony of about 2000 algae cells embedded in a gelatinous all area of glycoproteins and some cases are joined together by cytoplasmic filaments. Flagellated cells surface is coordinated so that the colony can be moved in the water. Usually does to the light, because it has very sensitive cells located predominantly bergstrom in the "northern hemisphere" of this "microplaneta". Each cell measures about 5 microns, but the colony can have half a millimeter or even reach 2 mm or more in some species. The largest can be seen with the naked eye. Volvox cells are specialized, or form part of reproduction or locomotion, bergstrom but do not have both functions bergstrom simultaneously. It's reproductive system is most fascinating, has asexual and sexual reproduction simultaneously. Within each of these areas grow within other areas are further colonies are called gonads Volvox. The gonads arise from cells in the "Ecuador" of the colony, but with the disadvantage of having flagella pointing inside of the sphere. To fix this problem further small colonies have to turn around like a sock when they are still small and are within their parent colony. Once they reach maturity mother colony ruptures releasing the new colonies that have grown inside, and that in turn lead granddaughters and colonies inside. Flagellated bergstrom surface cells. Photo: Wim van Egmond.
There are male and female colonies with specialized cells that form in the Ecuador or eggs or sperm. There are also hermaphroditic species, bergstrom but the production of sperm and eggs is not synchronized to avoid self-fertilization. The fertilized eggs, once developed, will form a new colony later, this time with genes from two individuals through this sexual reproduction. The Volvox may even have indoor inhabitants of other unrelated species. Specifically there is a kind of rotifer (Proales parasite) that can be introduced into living cells and algae (a parasite). The rotifer can detect if the colony is still. If this happens quickly perform a hole in the surface and escape. As you can see, the Volvox is a good model of organization intermediate stage between unicellular bergstrom organisms and more complex multicellular organisms. If you want to know how cooperation between individual bergstrom cells appeared to form a more complex system, the Volvox could provide clues. Cells of this kind are linked by Volvox cytoplasmic fibers. Photo: Wim van Egmond.
All macroscopic organisms have a unicellular ancestor and each group of creatures that now we had to suffer in the distant past a transition of this type. That changes in the cooperation and conflicts between individual cells led somehow and in some cases, at a resolution of these conflicts and the formation of colonies that would later evolve into multicellular organisms fully believed. This would have occurred sometime over 600 million years ago in the Neoproterozoic, but may have tried more times since. Until recently it was believed that the first Volvox appeared only 50 million years ago, but according to a new study, for which are used the most modern genetic techniques, these colonies have appeared about 200 million years ago during the Triassic. bergstrom At that time the world was populated by primitive dinosaurs, reptiles mamÃferoideos, tree ferns, ginkgo and some conifer. There were no flowers, no pollinating insects, no grass, no ruminants. According to Matthew D. Herron at the University of Arizona in Tucson, one of the authors of the study, Volvox cells went from being independent to being a colony in only 35 million years a parp
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