They convert glucose into usable energy.
        
             
        
        
        
Answer:
Scientists are perhaps some of the smart few that make up the human population and are never short on knowledge. They research and discover and conduct tests to gain more knowledge, but the answer to your question is stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores, and scientist know this because of their research.
Explanation:
 
        
             
        
        
        
<span>Primitive, single-celled life forms without organized nuclei are termed PROKARYOTES.</span>
        
             
        
        
        
So, lets say that the letter representing freckles is F for dominant or f for recessive
Clearly, the mother is F, while the father is f. which most likely gives the girls the genotype of Ff with one dominant freckle allele each which means they display the trait.
        
                    
             
        
        
        
Darwin's idea of the survival of the fittest means that certain organisms are more likely to survive with they traits in particular environments. This is because some organisms are more fit to live in a given environment whether it be due to temperature, weather, or predators.
One example is that dark moths are more fit for survival than light moths in many areas because they are able to camouflage against dark tree bark.
Hope this helps.