Oxygenated blood returns to the heart from the lungs via the

The primary source of protein for most of the world's population is

The complicated molecules that make up living things usually contain carbon. Why is carbon so important in these molecules? A. Carbon can form four strong covalent bonds. B. Carbon can only form one bond at a time. C.

In Mendel's crosses, the trait is visible in the F2 generation, but not the F1 generation.

You are recording the amount of heat that water can absorb before a temperature increase. What are you measuring? A.) The concentration of ions in seawater B.) The concentration of dissolved oxygen in seawater C.) The specific heat of seawater D.

The body of scientific knowledge related to nutritional requirements of human growth, maintenance, activity, and reproduction is known as

Two different species of birds live in the same habitat would be the same type of nesting place. As a result, both species will

Which of the following is NOT a type of synovial joint in the human body? A. pivot B. stirrup C. hinge D. gliding

What blood types are possible among the children of a cross between a man of blood-type A and a woman of blood-type B?

Which of the following is not a mechanism for biological evolution? a. Mutation b. Genetic drift c. Inheritance of acquired characteristic d. Natural selection

What factor explains why tundra biomes remain cold all year round the Taiga biomes have alternating warm and cold seasons? A. vegetation cover B. average precipitation C. altitude D. latitude