Mitochrondria of the eukaryotic cells.
<span>As many researchers hypothesize that the old single-celled organism or the origin of the complex-celled organisms came from the endosymbiosis of the mitochrondrion organism and the prokaryotic cell. It has been said that mitochondria was an independent organism which then to have been evovled itself after planting itself inside a prokaryotic cell which aided cellular respiration and production of ATP (Adenosine Triphosphate). This then aided the prokaryotic cell to be more sophisticated and caused another change from having without a true nucleus to a eukaryotic cell with a nucleus and embedded DNA. <span> 
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Answer:
Primary producers use energy from the sun to produce 
Explanation:
 Primary producers use energy from the sun to produce their own food in the form of glucose, and then primary producers are eaten by primary consumers who are in turn eaten by secondary consumers, and so on, so that energy flows from one trophic level, or level of the food chain, to the next.
 
        
                    
             
        
        
        
Answer:
I am pretty sure it's D. 
Explanation:
a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.
 
        
                    
             
        
        
        
Iron
A side note about haemochromatosis:
Haemochromatosis is a disease where there is too much iron is in the body.  It is the most common form of iron overload disease. There are two types of haemochromatosis: 
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Primary haemochromatosis is a genetic disorder inherited from family members.  People with this condition absorb too much iron and it ends up accumulating in the body, especially in the liver.   </span><span>
Secondary haemochromatosis is caused by other blood-related disorders such as anaemia, or may be due to many blood transfusions, long term alcoholism and/or other health conditions.    </span><span>If left untreated, iron overload can lead to liver damage. That’s why it’s important to receive treatment as soon as possible after diagnosis to prevent further complications, including liver disease, liver cirrhosis, liver failure, liver cancer, heart disease, arthritis or diabetes. Some organ damage can be reversed if detected early enough and treated appropriately.
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cigarettes
If you smoke cigarettes there’s a chance that you are causing damage to your liver – increasing your risk of developing liver cancer and decreasing your liver’s ability to rid your body of dangerous toxins. In turn, this could leave you more susceptible to the damaging effects of some medications on the liver too. </span>
 
        
             
        
        
        
(A)An adaptation is a characteristic that helps an animal survive in its habitat. All animals must be able to obtain food and water, protect themselves from harm, withstand the climate, and reproduce young so the species doesn't become extinct. ... Without their adaptations, the species could not thrive in that environment.
GIRAFFE-That ability – coupled with the tongue's impressive reach and its tough skin – allows giraffes to selectively browse, plucking leaves from among the nasty thorns brandished by many of its preferred food trees, such as acacias.