Proteins on the surface of a human cell and on a bird influenza virus are represented in the diagram below. Describe a change in the bird influenza virus that would allow it to infect this human cell.

Viral proteins can modify the most superficial portion in such a way that it is complementary to the receptor of the human cell.

Generally this happens due to a genetic recombination between an avian virus and a human virus within the respiratory epithelium of the pig: this process underlies the emergence of new, more virulent strains of the influenza virus and underlies the emergence of influenza pandemics

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .