The graafian follicle is the follicle that contains the secondary oocyte and after ovulation changes to a corpus leteum which secretes progesterone
        
             
        
        
        
Answer:
The correct answer is e. All of the above.
Explanation:
Sister chromatids are made during the synthesis phase of the cell cycle. In the synthesis phase, the homologous chromosomes get replicated and sister chromatids are produced so they are produced by duplication of chromosomes.  
As sister chromatids are produced by replication, therefore, they are identical copies of parent chromosomes. These sister chromatids are joined to each other at centromere. They get separated during the anaphase of mitosis and moves to the opposite pole. 
Therefore the right answer is e. 
 
        
             
        
        
        
I believe it would be sperm 
        
                    
             
        
        
        
Similar to the other types of muscle, smooth muscle contraction is caused by the sliding of myosin and actin filaments over each other. Calcium initiates contractions in a different way in a smooth muscle than in a skeletal muscle. 
Smooth muscles use less energy to generate the given amount of force, can substain contractile force without fatigue & uses calcium from the sarcoplasic reticulum & extracellular space.