A nucleotide is made up of one sugar molecule, one phosphate molecule and one of the four bases. Here is the structural formula for the four nucleotides of DNA. Note that the purine bases (adenine and guanine) have a double ring structure while the pyrimidine bases (thymine and cytosine) have only a single ring
        
             
        
        
        
To the ribosomes. Hope this helps :)
        
             
        
        
        
1) Arithmetic density- the number of people per square unit of land 
2) Physiologic density-  Is the number of people per square unit of farmland.
3) Agricultural density- is the number farmers per unit of farmland.
        
             
        
        
        
Answer:
I think it's an example of equilibrium 
 
        
             
        
        
        
Answer:
The correct answer is: A. Only the best-adapted animals in a population survive.
Explanation:
- Natural Selection is the process by which the individuals of a species which has the potential to sustain and survive in adverse or changing environment gets a survival advantage over those individuals which are unable to adapt themselves to altered environmental conditions.
- As the less potent individuals die in altered environmental conditions the  adaptable individuals escapes competition with them for natural resources.
- Evolution causes species to alter their characteristics depending upon the demand of the conditions. These changes can vary, can be less or drastic.
- Animals pass all the newly adapted traits to the successive generations either as genetic traits or as acquired traits, as this is necessary for the offspring to survive in the altered environment.
- Natural selection is best defined as "the survival of the fittest".