Ecosystem .. Just took the test !
Answer:
Human activity can affect the amount of carbon in the atmosphere. When fossil fuels like oil, coal, and natural gas are burned, carbon dioxide is released into the atmosphere as waste.
Explanation:
The alveoli. These little air sacs are found on the end of the bronchioles and are the place where oxygen enters the blood and the carbon dioxide leaves.
Answer:
Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair system for the body. There are two main types of stem cells: embryonic stem cells and adult stem cells
Explanation:
Totipotent (or Omnipotent) Stem Cells.
Pluripotent Stem Cells.
Multipotent Stem Cells.
Oligopotent Stem Cells.
Unipotent Stem Cells.
