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>
Molecules are defined as the smallest particles of a chemical compound or an element, and are made up of atoms. Cells are made up of semi permiable membranes that only allow selected materials to move in or out of the cell, therefore due to the big size of molecules compared to atoms the membrane doesn't allow their passage in the cell. Therefore the cell doesn't allow most molecules to diffuse passively to the cell. Secondly, molecules that can enter the cell requires specific carriers carriers that will enable entry of small molecules in the cell.
Explanation:
During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. ... Then, via respiration processes, cells use oxygen and glucose to synthesize energy-rich carrier molecules, such as ATP, and carbon dioxide is produced as a waste product.
