Answer:
Could you attach an actual pdf of the food chain so we can see?  
The producer is whatever makes the food for the first organism in the chain.
Explanation:
 
        
             
        
        
        
Answer:
Ginkgos and Cycads
Explanation:
Gymnosperm plants such as Ginkgos and Cycads have flagellated sperm.
 
        
                    
             
        
        
        
The answer is false. 
Because DNA only sends genetic info.
        
                    
             
        
        
        
Answer:
In experimental animals, such as mice, rats, and dogs, DDT has shown to cause chronic effects on the nervous system, liver, kidneys, and immune system.  It has also been found that humans, who were occupationally exposed to DDT, suffered chromosomal damage.
Explanation:
 
        
             
        
        
        
The correct answer is - accident.
In general, the invasive species are introduced into a new environment accidentally.This means that they have not been introduced on purpose, or in order to cause any harm to the ecosystem, though there are some exceptions.
The invasive species are usually very dangerous to the local ecosystem. The reason for that is that they usually do not have predators in the new ecosystem, or if they are the predators, than the local flora and fauna do not have defense mechanisms to cope with it. They also act very aggressively, have more offspring, as well as having the offspring on much shorter periods of time, which ends in occupying the space of the local organisms and even leading to their extinction.