Answer:
Used cross breeding to purposely breed plants. Studied a variety of pea plant traits. studied several generations of pea plants.
Explanation:
Because the cells can only use energy in form of ATP.
Its like you can't run a diesel truck on petrol.
Consider the nest to be (0,0)
The bird first flew 40 km (20x2) up and then 45km (15x3) left
So the final coordinates would be (40, -45)
