Could two humans have some differences in their dna sequences for insulin, yet still make the exact same insulin proteins? give a brief explanation.

DNA is copied and these copies are single stranded and called mRNA. mRNA gets translated and the information these mRNA-molecules have gathered from the DNA, triggers specific amino acids to bind and form proteins. 
One amino acid is coded from three bases on the RNA. So for example: ATG codes for one amino acid, and CGA codes for another. 
In many cases, different sequences can code for the same amino acid. For example: ATG and ATC results in the same amino acid.

That means that a difference in base sequence in the DNA can still result in the same protein being made. 

Competition. interaction among organisms that compete for the same natural resource (food, shelter, water, space) in an ecosystem. predation. an interaction in which one organism kills another for food. predator. prey. symbiosis. mutualisum. commensalisum. parasitisum.

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