Q: A solution has a pH of 4. What is the hydrogen ion concentration $$[H^+] of $$this solution?

$$[H^+] = 1 \times 10$$^{-4}$$ \ \mathrm{M}$$

Question 1

Which of the following best explains why carbon is unparalleled in its ability to form large, complex molecules essential for life?

Accepted Answer

Carbon can form up to four covalent bonds, allowing it to create diverse and stable structures such as chains, rings, and branches.

Question 2

A patient is diagnosed with anemia due to iron deficiency. Which of the following best describes why iron is considered a trace element and why it is added to the human diet?

Accepted Answer

Iron is required in small amounts for essential biological processes, such as oxygen transport in hemoglobin.

Question 3

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 4

A scientist is studying the cooling effect of sweating in humans. Which property of water is primarily responsible for this effect?

Accepted Answer

Evaporative cooling, which is due to water's high heat of vaporization.

Question 5

Which of the following best describes the difference between covalent and ionic bonds?

Accepted Answer

Covalent bonds involve the sharing of electron pairs between atoms, while ionic bonds involve the transfer of electrons from one atom to another.

Question 6

A solution has a pH of 4. What is the hydrogen ion concentration $$[H^+] of $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ \ \mathrm{M}$$

Question 7

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create a lattice structure that makes ice less dense than liquid water.

Question 8

A biologist observes a cell with a nucleus, mitochondria, and a cell wall. Which type of cell is being observed?

Accepted Answer

A plant cell

Question 9

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

Accepted Answer

Buffers minimize changes in pH by accepting or donating hydrogen ions ($$H^+) $$when acids or bases are added.

Question 10

Which of the following is a correct comparison between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar and is double-stranded, while RNA contains ribose sugar and is usually single-stranded.

Question 11

A researcher is using a transmission electron microscope (TEM) to study a cell. What is the main advantage of using a TEM over a light microscope?

Accepted Answer

A TEM provides much higher resolving power, allowing visualization of internal cell structures at the molecular level.

Question 12

Which of the following best explains the importance of compartmentalization in eukaryotic cells?

Accepted Answer

Compartmentalization allows different metabolic processes to occur simultaneously in separate organelles, increasing efficiency.

Question 13

Which of the following best describes the relationship between monomers and polymers?

Accepted Answer

Polymers are long chains made by joining many monomers through dehydration reactions.

Question 14

A person consumes a diet high in trans fats. According to scientific evidence, what is the primary health risk associated with this dietary choice?

Accepted Answer

Trans fats increase the risk of cardiovascular disease more than saturated fats.

Question 15

Which of the following best describes the function of the Golgi apparatus in eukaryotic cells?

Accepted Answer

It modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Question 16

Which of the following statements about the plasma membrane is correct?

Accepted Answer

The plasma membrane is composed of a phospholipid bilayer with embedded proteins, allowing selective permeability.

Question 17

A protein is denatured by exposure to high heat. Which level(s) of protein structure are most directly affected by this process?

Accepted Answer

Secondary, tertiary, and quaternary structures are disrupted, but the primary structure (amino acid sequence) remains intact.

Question 18

Which of the following best explains the endosymbiotic theory for the origin of mitochondria and chloroplasts?

Accepted Answer

Mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Question 19

A solution is made by dissolving 10 grams of NaCl in 100 mL of water. In this solution, which term best describes NaCl?

Accepted Answer

Solute

Question 20

Which of the following best describes the role of ribosomes in a cell?

Accepted Answer

Ribosomes are the sites of protein synthesis, translating mRNA into polypeptide chains.

BIO 1050 Exam I Study Guide: Chapters 1–4 (General Biology)

Guida di studio - Domande di pratica

Study guide - Flashcard