The answer for this question would be Integument, digestive, respiratory and urogenital.
The largest system that contact with the external environment would be integument and digestive. That makes two system has normal flora of microbes and not sterile like the other systems. Normal flora of microbes will prevent the pathogen microbe grows so it gives some benefit.
The answer is Dr Alec Jeffreys. <span>The genetic fingerprint and DNA profile are used by forensic science to help the police in their research work. The same technique has proved very useful in resolving litigation about paternity, for the identification of human remains in armed conflicts and for the identification of the corpses of historical figures.</span>
C. producer, the corn creates its own 'food' with photosynthesis. It's easier to remember as a flow chart producer(typically plants)->primary consumer(mostly herbivores)->secondary consumer(predators and other meat eaters) and decomposers(usually fungus) eat basically everything.
embryonic stem cells could serve as a model to evaluate the physiological effects of environmental pollutants efficiently and cost-effectively.
A chemical reaction bonding monomers together to make a polymer