The virus needs to speak the molecular language of cells. This is how he manages to dominate and enslave them so that they become factories for new viruses, producing the proteins that the infectious agent requires to assemble its descendants. If this conversation is not fine-tuned, even if the virus has the key and enters, it is doomed to failure.
<h3>Why does a virus lethal to us not infect animals?</h3>
For a virus to be able to enter a cell, it must have the right key. And this key, which are the proteins on the surface of viruses, has to enter the correct lock, the receptors that are on the cell membrane. Cells are actually houses with many different doors and locks. Some viruses have keys that open the lock of any cell and any kind of host, and others do not, so the infection caused by viruses is specific.
With this information, we can conclude that some viruses have keys that open the lock of any cell and any kind of host, and others do not, so the infection caused by viruses is specific.
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<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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I would have to say Proteins, lipids, and carbohydrates. Carbohydrates being the first energy source, lipids second and lasting the longest, and proteins the third and final source. although you did not give the full question, so i do not know if i can be completely sure.
Answer:
<em>Intervertebral Disc.</em> <em>The bodies of adjacent vertebrae are separated and united by an intervertebral disc, which provides padding and allows for movements between adjacent vertebrae.</em>
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<h3><em>Hope this helps!</em></h3>
