Hello there.
<span>Regulation of the cell cycle is dependent upon cyclins and cyclin-dependent kinases. The key(s) that allows a cell to progress beyond the restriction point is (are)
</span><span>c. cyclin A and Cdk2.
</span>
B
The other problems are not as easily solved; whereas, data collection over long periods of time is possible and was already done in the past, eg temperature and weather patterns. Therefore, this is the easiest limitation to overcome.
Galileo
<span>his observations helped support the Copernican view that the planets orbited the Sun, and not the Earth as previously believed.</span>
I think it is D for mountains form from the movement of tectonic plates which create volcanoes that erupt and form mountains
the eyebrows are proximal to the jaw
