That is true.
These are the three types:
Igneous- form when magma cools down and hardens.
Metamorphic- form under earth's surface after particles undergo intense heat and pressure.
Sedimentary- forms when different layers of sediment accumulate on top of each other and harden creating a solid piece.
Hope it helped!
Answer:
Alveoli are tiny, balloon-shaped air sacs. Their job is to move oxygen and carbon dioxide (CO2) molecules into and out of your bloodstream.
Explanation:
The answer is: the amount of the saliva samples must stay consistent while the amount of starch must vary.
The amount of the saliva samples must stay consistent because amylase, present in the saliva, is the independent variable which affects the dependent variable - the amount of starch. So, amylase will do its job while remaining surface area of the starch will depend on the starting amount of the starch.
The answer is d because natural selection is the process in which organisms adapt to their environment and all of these answers fall into examples of natural selection