Dinosaurs walked the earth at the same time that the first mammals appeared. these events coincided during which of the following periods? a. mississippian b. pennsylvanian c. permian d. triassic

An example of what is geese flying south for the

Which of the following is not a way in which a vascular plant's xylem and phloem are similar?

An ecologist is studying the effects that a population of predators is having on a population of a prey. he used data from the field to produce this graph. which conclusion can draw from the graph?