Inner core  was found to be solid after observing the motion of P waves.
Explanation:
Seismologist Inge Lehmann, studied the seismic waves of an earthquake and discovered about inner core in the mantle layer of Earth. She States that there is a boundary of discontinuity between the outer and inner core of Earth. 
She studied the travel of secondary and primary waves during an earthquake and how it flows at different shells of Earth's layer which helped her in finding about the inner core of mantle. She observed that the inner core is a solid layer inside the molten layer of outer core 
 
        
             
        
        
        
There are many lines of evidence which clearly show that the atmospheric CO2<span>increase is caused by humans.  The clearest of these is simple accounting - humans are emitting CO2 at a rate twice as fast as the atmospheric increase (natural sinks are absorbing the other half).  There is no question whatsoever that the CO2 increase is human-caused.  This is settled science.</span>
        
             
        
        
        
Answer:
The main difference between Prokaryotic and Eukaryotic cell is that, eukaryotes contain membrane bound organelles like nucleus where as prokaryotes do not. The genetic material is present at the center and is called nucleoid in prokaryotes. 
Explanation:
Example of prokaryotes include bacteria and archea bacteria. Examples of eukaryotes include plants and animals. Prokaryotes lack organelles such as mitochondria, endoplasmic resticulum and lysosomes which are present in eukaryotes. Both the groups contain ribosomes but its 70s ribosome in prokaryotes and 80s ribosomes in eukaryotes.
 
        
                    
             
        
        
        
Answer: both are made up of lipid bilayers. Main functions of both membranes are protection and transportation. Both are extremely important for the cell survival.
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