At what stage of pregnancy does an embryo show a beating heart and a complete central nervous system

Which of these processes causes a species to evolve? A. Natural selection B. Specialization C. Differentiation D. Natural variation

A possible explanation or answer to a question is a what?

What system breaks down food and what system transports nutrients to the cells of the body?

The genetic makeup of an organism is referred to as its

In California, average temperatures increase southward because of A topography B a decrease in latitude C the mixing of cold air and dry air D the prevailing winds

As líquid water freezes, the molecules take up more space than aqua water What do you think would happen if frozen water molecules required less space than liquid water molecules?

Which of the following mineral types can you use radiometric dating on? Homogeneous Inorganic Radioactive Ore

Which type of bond holds a water molecule together

Make a claim that answers the scientific question

A cow eating grass is an example of A) herbivory B) predation C) habitat destruction D) a keystone species