Echinoderm is the name given to a member of the phylum Echinodermata. They have radial symmetry and this includes sea urchins, sand dollars, sea stars and sea cucumbers. It is suggested that they are related to the chordates which is the answer.
        
             
        
        
        
The earth rotates around its axis as it revolves around the sun. it takes the earth one year to complete a revolution.
        
                    
             
        
        
        
The lac operon, which stands for Lactose operon is known as an inducible system. It is the an operon required for the transport and metabolism of lactose some enteric bacteria (Echerichia coli for example). The Lac operon is only activated in the presence of a key molecule. The key molecule is lactose.
From the given options the following best describes the Lac operon:
D. The repressor is freed from the operator when lactose is present.
 
        
             
        
        
        
I haven't taken biology since my freshman year of high school, so this is kind of a guess. But I know for sure it isn't a solid. So I would go with a gas.
        
                    
             
        
        
        
Answer:
Features of the ocean floor include the continental shelf and slope, abyssal plain, trenches, seamounts, and the mid-ocean ridge.
Explanation:
I'm gonna be honest.... I looked it up lol
Hope this helps!