The prefix for Bio is life so a biologist studies life of living organisms
The prefix for Geo is earth so it would be the study of earth.
What is in common would be animals and plants
what is different is an Geologist studies only earth Biologist studies everything living. I hope this was helpful and I didn't confuse you.
On the change in potential energy
Answer:
a. Potential energy decreases and Kinetic energy increases
Explanation:
Because as he comes down due to its steepness the speed of the boy or you can say his KE increases and since he comes from a high position (hill) to the lower ground his potential energy decreases simultaneously