<span>Na+, cl-, hco3-, and k+ are electrolytes. Na+ is sodium. Cl- is chloride. Hco3- is bicarbonate and k+ is potassium. Electrolytes are needed for our organs and cells to function like they should. We obtain some of these electrolytes through the food we eat, such as sodium from salt and potassium from bananas.</span>
Answer:
The first line of defense involves skin.
An increase in insulating atmospheric gasses (e.g. carbon dioxide)
Genes and DNA of their parents i think its those two <span />