Q: A solution has a pH of 4. What is the hydrogen ion concentration $$[H^+] of $$this solution, and how does it compare to a solution with pH 7?

$$[H^+] = 1 \times 10$$^{-4}$$ \ \mathrm{M}$$; it is 1,000 times more acidic than a solution with pH 7.

Question 1

Which of the following statements best explains why carbon is uniquely suited to form the backbone of macromolecules in living organisms?

Accepted Answer

Carbon can form up to four covalent bonds, allowing for a diversity of stable, complex structures.

Question 2

A solution has a pH of 4. What is the hydrogen ion concentration $$[H^+] of $$this solution, and how does it compare to a solution with pH 7?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ \ \mathrm{M}$$; it is 1,000 times more acidic than a solution with pH 7.

Question 3

Which of the following best describes the role of the sodium-potassium pump ($$\mathrm{Na^+/K^+}$$ ATPase) in animal cells?

Accepted Answer

It actively transports $$3 \ \mathrm{Na^+}$$ ions out of the cell and $$2 \ \mathrm{K^+}$$ ions into the cell, using ATP.

Question 4

A patient is given an intravenous solution that is hypotonic relative to their red blood cells. What is the most likely outcome for the cells?

Accepted Answer

Water will enter the cells by osmosis, causing them to swell and possibly burst.

Question 5

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The three-dimensional shape of the enzyme's active site is complementary to the substrate.

Question 6

During aerobic cellular respiration, which molecule acts as the final electron acceptor in the electron transport chain, and what is the product formed?

Accepted Answer

Oxygen ($$\mathrm{O_2$}$$); water ($$\mathrm{H_2O})$$

Question 7

Which of the following best describes the difference between facilitated diffusion and active transport across a cell membrane?

Accepted Answer

Facilitated diffusion moves substances down their concentration gradient without energy input, while active transport moves substances against their gradient using ATP.

Question 8

A DNA molecule is replicated in a semi-conservative manner. What does this mean for the resulting DNA molecules?

Accepted Answer

Each new DNA molecule consists of one parental strand and one newly synthesized strand.

Question 9

A woman with blood type AB ($$I^A I^B) $$and a man with blood type O ($$ii) $$have a child. What are the possible blood types of their child?

Accepted Answer

A or B only

Question 10

Which of the following is a direct result of crossing over during meiosis?

Accepted Answer

Increased genetic variation among gametes

Question 11

Which of the following best describes the function of restriction enzymes in biotechnology?

Accepted Answer

They cut DNA at specific sequences, allowing for the manipulation of genes.

Question 12

Which of the following is an example of microevolution observed in the modern world?

Accepted Answer

The development of antibiotic resistance in bacterial populations

Question 13

Which of the following best explains why cells are typically small in size?

Accepted Answer

A high surface area-to-volume ratio allows efficient exchange of materials with the environment.

Question 14

Which of the following best describes the role of buffers in biological systems?

Accepted Answer

They minimize changes in pH by accepting or donating hydrogen ions.

Question 15

A scientist observes that a protein loses its function after being exposed to high temperatures. What is the most likely explanation for this observation?

Accepted Answer

The protein has denatured, losing its three-dimensional structure necessary for function.

Question 16

Which of the following is a correct statement about the central dogma of molecular biology?

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 17

Which of the following best describes the difference between anabolism and catabolism?

Accepted Answer

Anabolism builds complex molecules from simpler ones, requiring energy; catabolism breaks down complex molecules, releasing energy.

Question 18

Which of the following is a property of water that is critical for life and is a result of hydrogen bonding?

Accepted Answer

High specific heat capacity

Question 19

A scientist wants to test the effect of a new fertilizer on plant growth. She sets up two groups: one receives the fertilizer, and the other does not. Which group serves as the negative control, and why is it important?

Accepted Answer

The group that does not receive the fertilizer; it allows comparison to determine the fertilizer's effect.

Comprehensive Study Guide for Introductory Biology (BIOL 110)

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