Q: A scientist is studying a solution with a pH of 4. Which of the following statements is correct regarding the hydrogen ion concentration and the nature of this solution?

The solution is acidic and has a higher concentration of $$\text{H}^+$$ ions than a neutral solution.

Q: A student measures the mass of an object as 27 grams and its volume as 6 milliliters. What is the density of the object, and what is the correct formula to use?

Density $$= \frac{\text{Mass}}{\text{Volume}} = \frac{27\ \text{g}}{6\ \text{mL}} = 4.5\ \text{g/mL}$$

Question 1

Which of the following best explains why ice floats on liquid water, and why this property is critical for aquatic life in cold climates?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds in ice are more 'ordered,' creating a crystalline structure that traps air. This floating ice insulates the water below, allowing aquatic organisms to survive winter.

Question 2

A scientist is studying a solution with a pH of 4. Which of the following statements is correct regarding the hydrogen ion concentration and the nature of this solution?

Accepted Answer

The solution is acidic and has a higher concentration of $$	ext{H}^+$$ ions than a neutral solution.

Question 3

Which of the following best describes the difference between a hypothesis and a scientific theory?

Accepted Answer

A hypothesis is a testable explanation for an observation, while a scientific theory is a broad explanation supported by a large body of evidence and can generate new hypotheses.

Question 4

A student measures the mass of an object as 27 grams and its volume as 6 milliliters. What is the density of the object, and what is the correct formula to use?

Accepted Answer

Density $$= \frac{	ext{Mass}}{	ext{Volume}} = \frac{27\ 	ext{g}}{6\ 	ext{mL}} = 4.5\ 	ext{g/mL}$$

Question 5

Which of the following statements about the structure and function of proteins is correct?

Accepted Answer

The primary structure of a protein, which is the sequence of amino acids, determines its final shape and function. A change in this sequence can result in a nonfunctional protein.

Question 6

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules are nonpolar and hydrophobic, so they do not form hydrogen bonds with water.

Question 7

A radioactive isotope has a half-life of 10 years. If you start with a 100 g sample, how much of the isotope will remain after 30 years?

Accepted Answer

$$12.5\ 	ext{g}$$

Question 8

Which of the following is a correct example of a dehydration synthesis reaction in biological systems?

Accepted Answer

Linking two monosaccharides to form a disaccharide, with the removal of a water molecule.

Question 9

Which of the following functional groups is correctly matched with its chemical properties and an example?

Accepted Answer

Carboxyl group (—COOH): acidic, found in amino acids and fatty acids

Question 10

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles, including a nucleus, while prokaryotic cells lack these structures.

Question 11

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

Accepted Answer

NaCl is the solute; water is the solvent.

Question 12

Which of the following is an example of a structural isomer?

Accepted Answer

Two molecules with the same molecular formula but different covalent arrangements of their atoms.

Question 13

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

Accepted Answer

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

Question 14

Which of the following best explains why water has a high specific heat capacity?

Accepted Answer

Hydrogen bonds between water molecules absorb heat when they break and release heat when they form, requiring more energy to change temperature.

Question 15

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

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 16

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds and are solid at room temperature; unsaturated fatty acids have one or more double bonds and are usually liquid at room temperature.

Question 17

Which of the following is a correct example of inductive reasoning in biology?

Accepted Answer

Observing that all examined cells contain DNA and concluding that all cells have DNA.

Question 18

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes act as catalysts by lowering the activation energy required for reactions, allowing them to proceed at body temperature.

Question 19

A student wants to convert 0.005 to scientific notation. Which of the following is the correct answer?

Accepted Answer

$$5 	imes 10$$^{-3}$$

Biology Foundations: Chemistry, Macromolecules, Cells, and Scientific Inquiry

Study Guide - Practice Questions

Study Guide - Flashcards