Answer:
I'm presuming you mean the three different subcatagories or taxa as there around 25/26 mammalian orders. The three taxa are - Prototheria or Monotreme = Mammals that lay eggs Metatheria Marsupial = Mammals with external development pouches.
Explanation:
Breathing and Heart rate cause oxygenated blood to be delivered to all tissues around the body
Answer: A) Organisms have cells with different shapes and functions.
Explanation: The cell theory explains that all organisms and plants are made of a basic structure or units, cells.
