YY and Yy would result in a plant with yellow seeds. This is because Y is dominant and yellow seeds would show with a dominant homozygous and a heterozygous. It can't be yy because that would be homozygous recessive 
        
             
        
        
        
omnivore⇒herbivore⇒autotroph
this is because an autotroph makes its own food (photosynthesis) so it doesn't have the need to eat other organisms. Herbivores eat only plans (remember this with the word herb is a type of plant) and an omnivore will eat either meat or plants so it can eat either of the things below it.
 
        
             
        
        
        
I’m definitely gonna say the first choice. The others don’t make much sense
        
                    
             
        
        
        
The goal was to see if Earth's ecosystems could be successfully manufactured and maintained elsewhere in the galaxy, should we need to bail on this planet.
It was named Biosphere 2 because it was meant to be the second fully self-sufficient biosphere, after the Earth itself