Is CGPA or Grade of New Students equal to their basic knowledge in science before they were accepted in to BS programme in science?

May be they need to sit for the qualifying test and replacement test before they start their proper bachelor programme. They did not show they have basic knowledge in science and geography such as world map, four seasons (winter, spring, summer and autumn). In fact I noticed they are not aware the right term to use and make wrong expression in their discussion. They know surely birds laying eggs but they still say birds lactate their offspring. Why this thing can be seen among the university students. Education systems, students are not serious in answering the questions or they really low quality. BUT their grades are above 3.0 and some of them awarded a scholarship. Something need to be done immediately.