An individual eats a hamburger. which two systems must interact to transfer the nutrients in the hamburger to human muscle tissue?
(1)respiratory and excretory
(2)digestive and immune
(3)digestive and circulatory
(4)circulatory and respiratory

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: