Answer:
Cells have many structures inside of them called organelles. These organelles are like the organs in a human and they help the cell stay alive. Each organelle has it's own specific function to help the cell survive. The nucleus of a eukaryotic cell directs the cell's activities and stores DNA.
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Answer:
Homeostasis
Explanation:
 Homeostasis- state of maintaining a stable internal enviornment despite changing external conditions
 
        
             
        
        
        
Answer:
Microtubules composed of tubulin protein. 
Explanation:
The cytoskeleton is composed of three well defined filamentous structures: microtubules, microfilaments, and intermediate filaments. Each of these filamentous structures is a polymer of proteinic subunits united by weak, not covalent connections. 
Microtubules are long hollo cylindric tubes with no ramifications of a diametre near to 25 nanometers. They are constituted by two subunits of tubulin protein which polymerize to form microtubules. These filaments shape the cell and are involved in intracellular transport.  Microtubules extend from an organizing center near the nucleus to the cellular surface. 
 
        
             
        
        
        
Answer:
Most humans cannot see ultraviolet light because it has a smaller wavelength than violet light, putting it outside of the visible spectrum.

 
        
             
        
        
        
Answer:
yes the answer are actually very correct