I suggest you to provide some options, as it's quite difficult to answer your question. Here is your answer: A long bone is covered externally with a sheath called the 
periosteum, whereas the marrow cavity is lined with the <span>
endosteum</span>
. I've attached the illustration to make it clear for you
 
        
        
        
I'm sorry, but is this a question? I'm a bit confused.
        
                    
             
        
        
        
Answer:
sexual reproduction, because the genetic material comes from both parents.
Explanation:
The sperm and egg produced contain different combination of genes