Down syndrome is a condition in which the individual

a. has three copies of chromosome 21.

b. has three copies of chromosome 23.

c. lacks chromosome 46.

d. has only one chromosome 21.

During which period did T. Rex reign? A. Permian B. Triassic C. Jurassic D. Cretaceous

Susan is a geological researcher measuring the rate of removal of phosphorous from sedimentary rock during the phosphorous cycle. What process is Susan investigating?

In considering the reactions between molecules unique to living systems-carbohydrates, lipids (fats), proteins, and nucleic acids-which molecule does not rely on hydrolysis reactions

The Bible gives us no information about science ... True or false? I'm assuming false but also I'm taking a quiz and don't want to get it wrong.

1. All living organisms contain carbon atoms. Which of the following is an important characteristic of carbon?

When a nurse rubs your skin with rubbing alcohol prior to administering an injection, what process (es) is he carrying out? select all that apply?

Which of these is not an organism? a) lungs b) bacteria c) mold d) human

Why might to elements proces why might to elements possess similar chemical properties?

What happens in the electric circuit when the magnet spins?

An enzyme used to covalently join dna segments to form recombinant dna molecules is called a