Practice Science Test #1 Questions 11-20

Which statements most accurately compares and contrasts the structures of DNA and RNA?

a. Both DNA and RNA have 4 nucleotide bases. Three of the bases are the same, but the fourth base is thymine in DNA and uracil in RNA

Fill in the blanks in the following sentence

Enzymes are __________ molecules that serve as ___________ for certain biological reactions.

d. large; catalysts

What type of molecules are enzymes?

b. Protein molecules

Which blood vessel carries oxygenated blood back to the heart?

a. Pulmonary vein

Mrs. Jones’s class is conducting an experiment. They will substitute an artificial sweetener for sugar in a cookie recipe to determine the effect on the overall color of the baked cookies. Which of the following should be included in the instructions for the experiment?

d. Ingredient proportions, bake time, bake temperature, and cookie sheet material should all be kept the same between the two batches of cookies to avoid confounding factors

An atom has 5 protons, 5 neutrons, and 6 electrons. What is the electric charge of this atom?

c. Negative

How many different types of tissue are there in the human body?

a. 4

Of the following, the blood vessel containing the least oxygenated blood is the:

c. Pulmonary artery

Refer to the following questions 19-20:

“ A student is conducting an experiment that is attached to the end of a string, forming a pendulum. The student pulls the ball back so that it is at an angle to its resting position. As the student releases the ball, it swings forward and backward. The student measures the time it takes the ball to make one complete period. A period is defined as the time it takes the ball to swing forward and back again to its starting position. This is repeated using different string lengths.”

The student formed the following hypothesis:

Lengthening the string of the pendulum increases the time it takes the ball to make one complete period.

What correction would you have the student make to the hypothesis?

a. Turn it into an “if / then” statement

What would be an appropriate control variable for this experiment?

c. The mass of the ball