Why does the human heart rate increase when exercising? explainwhat is the difference between a simple and a complex carbohydrate? describe an advantage to being multicellular. two organisms are in the same phylum but not the same class. another pair of organisms are in the same genus. which pair has more in common? why? describe how lungs develop. describe how a giraffe meets the basic challenges of life. how can someone determine if something is a living organism? pls answer

Your heart needs to pump back extra oxygen up to the muscles, breathes fastens up as you need oxygen, and to get rid of carbon dioxide 

Carbohydrates are sugars that come in two ways, it is simple and complex. The difference is that how it is absorbed. And how the way the chemical is made.

The advantages are that an organism can be larger, cell differences, and as well for the organisms to be more complex.

Because genus means the same, meaning that they are in the same kingdom, family, and genus which is what I am mentioning.

Around 4-6 weeks two tiny buds start to bring out, one forms the other long and as well as the other side. At around the 17th week the buds that were formed on the 4th week, they start to branch out smaller and smaller as time happens each bud develops and blood starts going up to the lungs creating oxygen.

Giraffes have horns on top of their heads to help them fight when they are in danger. They have long necks to help them eat trees, usually when they get dehydrated they can still be hydrated because of the moisture from the leaves. They are also prey to a lot of animals who eat meat, so giraffe population will reduce.

First is that they are made of cells, second is that living things reproduce, and third they adapt to their environment.