Answer:
Two groups of proteins, called cyclins and cyclin-dependent kinases (Cdks), are responsible for the progress of the cell through the various checkpoints. Cyclins regulate the cell cycle only when they are tightly bound to Cdks.
Explanation:
They show a high degree of contact inhibition
The answer is B. Cost of maintaining a power plant
Lead emission since early 1980s have DECREASE DUE TO LEAD FREE GASOLINE.
Lead is a natural occurring element that is found in small quantity in rocks and soils. Lead emission is an important environmental health issue because a very small quantity of lead can cause adverse effects on the nervous system of unborn babies and young children. Because of this, the government took all necessary measures to ensure that its emission was drastically reduced.
