The hypothesis that all modern humans descended from an African lineage is supported by the mitochondrial DNA evidence. The Eve hypothesis is the hypothesis that is based on the study of mirtochodrial DNA; that modern humans have a common female ancestor who lived in Africa around 200,000 years ago. It is also called African Eve hypothesis. 
        
             
        
        
        
Answer:
I would assume D
Explanation:
Tube 1 doesn't contain an organism so it can't be that one. Both a snail and a plant are considered an organism, and cellular respiration occurs in almost any organism's cells
 
        
             
        
        
        
Answer: As in other higher vertebrates, the frog body may be divided into a head, a short neck, and a trunk (see Vertebrates). The flat head contains the brain, mouth, eyes, ears, and nose. A short, almost rigid neck permits only limited head movement. The stubby trunk forms walls for a single body cavity, the coelom.
Explanation:
 
        
             
        
        
        
The organisms<span> that eat the producers are the primary consumers. They tend to be small in size and </span>there<span> are many of them. ... Because of this inefficiency, </span>there<span> is only enough </span>food<span> for a </span>few top<span> level consumers, but </span>there<span> is lots of </span>food<span> for herbivores lower down on the </span>food chain<span>.</span>