Although all human body systems are necessary for survival, how do the circulatory and respiratory systems provide vital substances to every cell in the human body? Why does a failure of either of these systems quickly lead to possible death?​

Why do you think the puppy litter was all dark-haired?

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.