Cell Membrane is the answer
        
                    
             
        
        
        
My Answer: Vestigial organs
Why?: " Vestigial organs are physical structures that were fully developed
and functional in an ancestral group of organisms but are reduced
and unused in the later species."
Hope I helped! :D
        
             
        
        
        
I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
        
             
        
        
        
Answer:
Both animal and plant cells have mitochondria, but only plant cells have chloroplasts. Plants don't get their sugar from eating food, so they need to make sugar from sunlight. Because animals get sugar from the food they eat, they do not need chloroplasts: just mitochondria.
Explanation:
 
        
                    
             
        
        
        
Answer:
D -herbivore population sizes decrease ,then the carnivore population sizes decrease