3 is the correct answer. Let me know if you want me to explain why that is the answer.
Nicotine, once in the brain, will work specifically on nicotinic receptors in the brain. However, there is a common "addiction" pathway in the brain that pretty much all addictive substances go through.
He begins by discussing how horizontal transfer can move genetic material between bacteria. Transformation, transduction, and conjugation in bacteria are all included. He also explains how crossing over, random assortment, and random fertilization can maintain genetic variation in eukaryotes.
Answer:
Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy. Many enzymes change shape when substrates bind.
Explanation:
