The purines are:

adenine and guanine

cytosine and guanine

cytosine and thymine

ribose and deoxyribose

Bones can only assist in providing movement when they tugged on by the appropriate skeletal muscles. True or false?

The brain is the key organ in which system

A parent has blue eyes and passed this characteristic on to his child. Which molecule contains the information necessary for passing on this characteristic? protein DNA lipid enzyme

Why are electrical signals in the body are often based on ions?

A 3-year-old is making play cakes in a sandbox and is eating the play cakes. The sand was also being used by cats as a litter box and was contaminated with toxoplasmosis. Which of the following would most likely be present? A. Granuloma formation. B.

Which level of biological classification is the lowest level that butterflies

What might happen if a continent stops rifting apart?

Write the least common multiple of 7 and 14

How long do footprints last at the sene of the crime?

Which of the following items would have the highest density? A. A 2 cm3 block of lead with a mass of 11 grams B. A 12 cm3 block of wood with a mass of 3 grams C. A 12 cm3 block of aluminum with a mass of 2 grams