The presence of alveoli in birds aids in:

 Cephalization is present in:

 Which of the following is a group of cells that perform a similar function?

 Which class is characterized by cartilaginous skeletons and rows of teeth?

Which class of fish lacks jaws?

 Mammary glands in mammals serve what function(s)?

The tissue that gives rise to muscles and much of the circulatory system is:

 In protostomes, the blastopore becomes the:

Which process defines how molecular compounds form ions upon dissolution?

When a chemical equation is balanced, it will have a set of whole number coefficients that cannot be reduced to smaller whole numbers. What is the coefficient for O2 when the following combustion reaction of a hydrocarbon is balanced? ___ C7H14 + ___ O2 → ___ CO2 + ___ H2O