You have learned that both biotic and abiotic factors affect ecosytems. Give some examples of each and explain how biotic and abiotic factors could have affected the tortoises that Darwin observed on the Galápagos Islands.​

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

the answer is cell division : )