Imagine a population of small animals. All of the animals in this population have short legs. They all eat the leaves off of the low shrubs in their environment. One animal happens to be born with a mutation that gives it very long legs. It is the only individual in this population with this mutation, and it makes it very hard for it to eat the leaves so low to the ground. But suddenly there is a fire that burns all of the shrubs, so the only food source is now up in the low tree branches. How might this individual animal with the long-leg mutation affect the entire population?

It can mate with the other animals and have long legged offspring. This would evolve their species into adapting to their new environment.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

69 is the correct math for the amino acids