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

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

Question 1

Which of the following best explains why water is able to moderate temperature changes in living organisms?

Accepted Answer

Water has a high specific heat due to hydrogen bonding between molecules.

Question 2

A scientist is studying a molecule with the formula $$C_{6}H$$_{12}$$O_{6}$. Which class of macromolecule does this molecule most likely belong to, and what is its primary function in the human body?

Accepted Answer

It is a carbohydrate; its primary function is providing immediate energy.

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 patient is diagnosed with iron-deficiency anemia. Based on your knowledge of trace elements, which of the following best explains the importance of iron in the human diet?

Accepted Answer

Iron is a trace element necessary for the transport of oxygen in the blood.

Question 5

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

Accepted Answer

Covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons.

Question 6

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

Accepted Answer

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

Question 7

Which property of phospholipids makes them essential for forming biological membranes?

Accepted Answer

They have both hydrophilic heads and hydrophobic tails, allowing them to form bilayers.

Question 8

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

Accepted Answer

Hydrogen bonds in ice hold water molecules farther apart, making ice less dense.

Question 9

A researcher observes a cell with a nucleus, mitochondria, and chloroplasts. Which type of cell is this most likely to be?

Accepted Answer

A eukaryotic plant cell

Question 10

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

Accepted Answer

Buffers maintain a stable pH by accepting or donating hydrogen ions as needed.

Question 11

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

Accepted Answer

DNA is usually double-stranded, while RNA is usually single-stranded.

Question 12

A protein is exposed to high heat and loses its three-dimensional structure. Which level(s) of protein structure are most directly affected by this process?

Accepted Answer

Secondary, tertiary, and quaternary structures

Question 13

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

Accepted Answer

As cells increase in size, their volume increases faster than their surface area, limiting efficient exchange of materials.

Question 14

Which of the following is a function of the Golgi apparatus in eukaryotic cells?

Accepted Answer

Modifying, sorting, and packaging proteins for secretion

Question 15

A molecule contains a long hydrocarbon chain and a carboxyl group. To which class of biological macromolecules does it most likely belong?

Accepted Answer

Lipids

Question 16

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

Accepted Answer

Ribosomes are involved in protein synthesis by linking amino acids together.

Question 17

Which of the following scenarios best illustrates the concept of dehydration synthesis?

Accepted Answer

Two amino acids are joined together to form a dipeptide, releasing a molecule of water.

Question 18

Which of the following best explains the adaptive advantage of compartmentalization in eukaryotic cells?

Accepted Answer

It allows for the separation of incompatible chemical reactions and increases efficiency.

Question 19

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

Accepted Answer

The plasma membrane is composed primarily of a phospholipid bilayer with embedded proteins.

Question 20

A scientist observes a cell with no nucleus, circular DNA, and no membrane-bound organelles. Which type of cell is this most likely to be?

Accepted Answer

A prokaryotic cell

General Biology Exam I Study Guide: Chapters 1–4

Guida di studio - Domande di pratica

Study guide - Flashcard