A new moon 
Definition of new moon:
the phase of the moon when it is in conjunction with the sun and invisible from earth, or shortly thereafter when it appears as a slender crescent.
        
             
        
        
        
Darwin's theory of Natural Selection
        
                    
             
        
        
        
Mechanical stress applied to bone increases osteoblast activity in bone tissue, and the removal of mechanical stress decreases osteoblast activity.
Explanation:
Osteoblasts are cells , that are produced in the bone marrow and are responsible for formation of bones and bone matrix.
Whenever a mechanical stress is applied on the bones , a series of reactions are triggered. As a result the activities of osteoblast increases to synthesize more and more bone matrix to provide strength.
Again on the other hand a decrease in mechanical causes a decrease in the activities of the osteoblasts.
 
        
             
        
        
        
Eukaryotic cells are larger than prokarotic cells and have a true nucleus membrane bound organelles and rod shaped chromosomes.The nucleus houses the cells DNA and directs the synthesis of proteins and ribosomes.Mitochondria are responsible for ATP production the endoplasmic reticulum modifies proteins and synthesizes lipids and the golgi apparatus is where the sorting of lipids and proteins takes place.
        
             
        
        
        
Roots....................