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There are two reasons why a Hydra does not need a circulatory system. 1) It is small. The body wall has only two cell layers separated by a non-cellular layer, xo substances have only a short distance to move. Over these short distances diffusion is adequate. 2) It has a large surface area compared with its volume (large SA:V ratio). This is because its body is hollow, so it can absorb substances over the inner surface as well as the outer surface. See http://en.wikipedia.org/wiki/Circulation_%28physiology%29
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∙ 16y ago
Single-celled organisms are simple in structure and their small size allows for efficient exchange of gases, nutrients, and waste products directly through their cell membrane. They lack the complexity and scale that would necessitate separate organ systems for these functions. Their small size also means that they have a large enough surface area-to-volume ratio to meet their metabolic needs without the need for specialized organs.
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∙ 14y agobecause of diffusion, small organism do not need circulatory system because thy are too small
Wiki User
∙ 13y agoNutrients and gases can diffuse directly across the cell membrane, thereby eliminating a need for such a complex system!
Wiki User
∙ 12y agobecause they dont.
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∙ 10y agor54e769
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What is one difference between one-celled organisms and cells in a organ?
One key difference is that one-celled organisms, like bacteria or protists, are complete living entities on their own, whereas cells in an organ are part of a multicellular organism and depend on other cells for survival. Cells in an organ are typically specialized for specific functions to contribute to the overall function of the organ, while one-celled organisms must perform all necessary functions independently.
Do more complex organisms need more energy than simpler organisms?
Yes, generally more complex organisms require more energy to support their increased metabolic demands. This is because complex organisms have more specialized cells and tissues, perform more complex functions, and require larger and more efficient organ systems to sustain their body functions.
Why bacteria cannot have organs?
Bacteria are single-celled organisms without complex internal structures like organs. They lack specialized tissues and organ systems found in multi-cellular organisms because they are unicellular and have a simple structure with no need for organs to carry out their basic functions.
Why don't plants require complex organ systems?
Plants do not require complex organ systems like animals because they have evolved different strategies to meet their needs. They utilize structures like roots, stems, and leaves to carry out essential functions such as absorption, support, and photosynthesis. These structures can perform multiple roles efficiently without the need for specialized organs.
Does mitochondria stop functioning in a unicellular organism exposed to pollutants indicates organ system?
Yes, if a unicellular organism is exposed to pollutants, it can disrupt mitochondrial function, leading to decreased energy production and eventual cell death. This disruption can impact the entire organism since unicellular organisms do not have specialized systems like organ systems to compensate for the loss of function in mitochondria.
Do all organisms need an organ?
Not every organism need organs.Unicellular organisms do not have any way.
Do all organisms have a organ system?
No, not all organisms have an organ system. Some organisms, like single-celled bacteria or protists, do not have organ systems as their basic structure is simpler and doesn't consist of specialized organs working together in a system.
Why does the arm need many organ systems?
Just does. Deal with it.
Why do you need to study the human organ systems?
because this is our human body
What is one difference between one-celled organisms and cells in a organ?
One key difference is that one-celled organisms, like bacteria or protists, are complete living entities on their own, whereas cells in an organ are part of a multicellular organism and depend on other cells for survival. Cells in an organ are typically specialized for specific functions to contribute to the overall function of the organ, while one-celled organisms must perform all necessary functions independently.
Are organ systems related?
They all work together to make an organism.
Why have large organisms devolped systems like the respirtory system?
because they need to breath!
Do more complex organisms need more energy than simpler organisms?
Yes, generally more complex organisms require more energy to support their increased metabolic demands. This is because complex organisms have more specialized cells and tissues, perform more complex functions, and require larger and more efficient organ systems to sustain their body functions.
Why bacteria cannot have organs?
Bacteria are single-celled organisms without complex internal structures like organs. They lack specialized tissues and organ systems found in multi-cellular organisms because they are unicellular and have a simple structure with no need for organs to carry out their basic functions.
Why does the body need so many organs systems?
Each organ system is specialized with doing only one job.
Why don't plants require complex organ systems?
Plants do not require complex organ systems like animals because they have evolved different strategies to meet their needs. They utilize structures like roots, stems, and leaves to carry out essential functions such as absorption, support, and photosynthesis. These structures can perform multiple roles efficiently without the need for specialized organs.
Does mitochondria stop functioning in a unicellular organism exposed to pollutants indicates organ system?
Yes, if a unicellular organism is exposed to pollutants, it can disrupt mitochondrial function, leading to decreased energy production and eventual cell death. This disruption can impact the entire organism since unicellular organisms do not have specialized systems like organ systems to compensate for the loss of function in mitochondria.
