Metabolic pathways stimulate cell division.
Answer:
Every organisms on the planet requires a specific environmental conditions for its growth and survival. If the environmental condition is favorable, the organisms grow fast and if the conditions are not suitable so it adversely affected the organisms. For example, plants grow best at the temperature between 25 to 40 Celsius. If the temperature goes below 25 or above 40, the growth decrease and sometimes the plant dies. So climate and abiotic factors such as temperature, humidity, light intensity etc has a great impact on the organisms.
The activity of some enzymes requires vitamins. This is because vitamin derivatives contribute to the biochemical mechanisms of these enzymes. These vitamin derivatives belong to a class of molecules known as cofactors, which are organic molecules (called coenzymes) or metallic ions, that assist in the catalytic activity of an enzyme.
Direct observation is an observation you make first hand. It is something you see with your own eyes and observe yourself.
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