Scavengers play an important role in the network of food. They keep the world clean from the remains of dead animals, or carrion. Scavengers break down this raw material and recycle it as nutrients into the environment. Vultures consume only the corpses of deceased animals.
        
             
        
        
        
It would be d because a cell is least complex and organ system is most complex
        
             
        
        
        
Wild boars were brought to the United States by humans.Wild boars have quickly spread through the United States.Wild boars have established successfully in areas with warm climates.<span>Wild boars have a high reproductive rate and no natural predators. the answer is (c)
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The correct matching of enzymes and their role in the process of DNA replication is A- 3, B- 5, C-1, D-2 and E-4.
Replication is the process of synthesis of two indentical copies of DNA from a single DNA molecule. It is catalyzed by a set of enzymes with the following function-
A. RNA primase synthesizes an RNA primer (short sequence of RNA) on the lagging strand complementary to the single stranded DNA which acts as template during DNA replication.
B. Ligase is involved in joining the okazaki fragments on the lagging strand together and sealing the nicks of the DNA strand. 
C. Helicase separates the two DNA strands at the replication fork.
D. Polymerase synthesizes the complementary daughter strand by adding nucleotides to DNA.
E. Topoisomerase relaxes the highly coiled DNA by creating nick ahead of the replication fork in the phosphate backbone of DNA strands.