Question 1

Which statement best describes the organization of biological systems from smallest to largest?

Accepted Answer

Atoms make up molecules, molecules make up cells, cells make up tissues, tissues make up organs, and organs make up organisms.

Question 2

Which of the following is NOT a form of energy relevant to biological systems?

Accepted Answer

Magnetic energy

Question 3

According to the first law of thermodynamics, which of the following is true?

Accepted Answer

Energy is neither created nor destroyed, only transformed.

Question 4

A perpetual motion machine is impossible because:

Accepted Answer

It violates the laws of thermodynamics, as energy is always lost to friction and heat (entropy).

Question 5

If you want to lose one pound of fat, how many more calories must you burn than you consume?

Accepted Answer

$$3500$$

Question 6

Which four elements make up approximately 96% of the mass of living organisms?

Accepted Answer

Carbon, Hydrogen, Oxygen, Nitrogen

Question 7

What is the molar mass of glucose ($$C_6H_{12}O_6$)? Use atomic weights: C=12$, H=1$, O=16$.

Accepted Answer

$$180$$ grams/mol

Question 8

Which statement about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 9

Radioactive tracers are useful in medicine because:

Accepted Answer

They can be used to track atoms through metabolism and diagnose diseases.

Question 10

Which of the following best describes a covalent bond?

Accepted Answer

A sharing of a pair of valence electrons between atoms.

Question 11

Water ($$H_2O) is an $$example of a molecule with:

Accepted Answer

Polar covalent bonds

Question 12

Which type of bond is responsible for holding the two strands of DNA together?

Accepted Answer

Hydrogen bonds

Question 13

What is the main reason ionic bonds are weaker in biological (aqueous) environments than covalent bonds?

Accepted Answer

Water disrupts the electrostatic attraction between ions.

Question 14

Which of the following is a real-world application of radioactive isotopes?

Accepted Answer

Radiometric dating of fossils

Question 15

If you dissolve $$180$$ grams of glucose ($$C_6H_{12}O_6$) in 1$ liter of water, what is the molarity of the solution?

Accepted Answer

$$1 M$

Question 16

Which of the following best explains why molecular shape is important in biology?

Accepted Answer

Molecular shape determines the function and interactions of molecules, such as enzyme activity and receptor binding.

Question 17

Which equation represents the chemical reaction for photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 18

What is chemical equilibrium in a reaction?

Accepted Answer

The point at which the forward and reverse reactions occur at the same rate and the concentrations of reactants and products remain constant.

Question 19

Which of the following is a property of van der Waals interactions?

Accepted Answer

They are short-term, weak attractions due to temporary asymmetrical electron distributions.

Question 20

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally between atoms, resulting in partial charges.

The Chemical Context of Life: Foundations for General Biology

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