Environment, genetics, selective breeding, random mating, random fertilization, recombination, crossing over, etc
        
             
        
        
        
Answer:
1. Alzheimer's disease is when you begin to forget things and have memory loss.
2. It is inherited in an autosomal dominant pattern and if one of your parents has Alzheimer's you or your siblings could get it.
3. Single gene inheritance
Explanation:
 
        
             
        
        
        
Answer:
Some mutagens strip DNA nucleotides (bases) of essential modifications—for example, they deaminate the bases—such that these bases resemble different nucleotides and confuse the DNA replication machinery. Subsequent rounds of DNA replication then permanently incorporate such changes.
Explanation:
 
        
             
        
        
        
Ileostomy is a procedure where the end of the small intestine, called the ileum, is brought out of an opening in the belly through surgery. The opening is called a stoma, and its shiny, bright red in color. It is often done after the large intestine has been removed due to cancer or serious physical injuries. Having a stoma, and the need of emptying it several times a day, is disfiguring so the patient often suffer from poor self image. The patient in the case, may be concerned of being unable to continue romantic relationships due to having a stoma. As a nurse, make sure to first make patient understand that ileostomy surgery does not involve the reproductive organs or the gonads. Then, acknowledge that while having a stoma is disfiguring, many organizations are helping increase awareness and acceptance of those who have the condition. Refer the patient to such local stoma advocacy organizations. 
        
             
        
        
        
To see the solar eclipse it is rare because the moon doesn't hide all of the sun up.