I think the correct answer from the choices listed above is option A. Sickle cell disease is caused by a change in allele. It is a disorder of the blood caused by an inherited abnormal hemoglobin. Hope this answers the question. Have a nice day.
        
             
        
        
        
There are many fish in the world.
but it’s probably not that hard tbh.
        
             
        
        
        
Answer:
The xylem is located in the root, stem and the leaves of a plant.
The xylem contains dead cells arranged end-to-end forming continuous vessels. They have a hollow central space (lumen)  through which water passes. They walls contain lignin. 
The xylem carries water and minerals, up from the roots to the rest of the plant.
 
        
             
        
        
        
<span>living things ................</span>
        
             
        
        
        
Chloroplasts are cell organelles that are key in the process of photosynthesis.
The chloroplasts have two distinct parts, one of them called the thylakoid containing the chlorophyll, a pigment essential for photosynthesis and the stroma, a liquid part that contains DNA molecules, enzymes, and ribosomes.