The branched structure of human lungs significantly increases the surface area for gas exchange which increases the efficiency of gas exchange with the lungs.  Which theme of biology does this example illustrate? 

Which substance is NOT recycled but moves through an ecosystems? 

Sugar dissolves when stirred into coffee. The coffee is the ________, the sugar is the ________, and the sweetened coffee is the ________. 

Information about Trans Fats is reported on the Nutrition Facts Label of food items.

A single carbon atom can form a maximum of ________ covalent bond(s). 

A(n) ___________ variable is the treatment in an experiment while the ___________ variable is what is measured as an outcome. 

Humans store excess glucose in the form of a polysaccharide called 

The ___ provided US finances to help pay for a European plan to rebuild war-torn Europe after WWII.

An apparent turning motion that affects large masses of air as the Earth rotates on its axis is the:

Which specific region of the world is experiencing Stage 4 population growth?