Brain energy requirement, metabolism and neurotransmitter turnover consume 20 % of the available oxygen and glucose in the body. 
  <span>Even though, the brain is only about 2% of the body weight, it consumes about 20% of the body's energy. It is the main consumer of glucose-derived energy. When the mental strain increases, the brain's demand for energy in the form of oxygen and glucose is higher.</span>
        
                    
             
        
        
        
Answer:
I don't know sorry need kalng points HAHAHAHAHAHA
 
        
             
        
        
        
Answer:
<em>The correct option is C) AS</em>
Explanation:
Sickle cell anaemia is a recessive disorder in which the blood of the person is not able to clot properly. For sickle cell to occur, both the alleles for the trait have to be recessive. A person who has a dominant and a recessive allele will be heterozygous, showing the dominant characteristics. But such a person will be a carrier for the disease. There will be chances for the offsprings of that person to actually have the disease. 
 
        
             
        
        
        
If there is limited of food then they will compete but if there is an equal amount of food they won’t compete. So the answer is true.
        
                    
             
        
        
        
bottleneck effect --- > A disease wipes out almost 90% of a population of birds, but the species adapts, and after 5 years its numbers increase dramatically.
gene flow --->  A population of rats travels on a cargo ship and mate with rats in a new region.
founder effect ---> Biologists introduce a small population of lizards on an island as part of a conservation effort.
mutation ---> A change in a DNA sequence causes a lizard to develop a darker skin color, which helps it hide from predators.