The first two blanks are evidence of climate change, third blank is the main cause of climate change, and the fourth blank is a mechanism by which climate change occurs.
These animals were living in an environment with a warm climate that results in changing sea levels. These conditions create a lot of shallow inland seas allowing these animals to thrive. The Cretaceous period is the last period of the Mesozoic area where new groups of mammals, birds, and flowering plants appeared on Earth.
Cells divide for many reasons. For example, when you skin your knee, cells divide to replace old, dead, or damaged cells. Cells also divide so living things can grow. When organisms grow, it isn't because cells are getting larger.
Enzymes <em><u>act as catalysts in Chemical reaction of cells. </u></em>And they <u><em>can lower the required activiation energy for reaction in living organisms. </em></u>