Question 1

Which of the following best describes the relationship between atoms, molecules, and macromolecules in biological systems?

Accepted Answer

Atoms combine to form molecules, which then combine to form macromolecules essential for life.

Question 2

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

Accepted Answer

The formation of a peptide bond between two amino acids, releasing a molecule of water: $$\ce{R-COOH + R'-NH2 \rightarrow R-CO-NH-R' + H2O}$$

Question 3

A scientist is studying the effect of pH on enzyme activity. Which variable should be considered the independent variable in this experiment?

Accepted Answer

The pH of the solution

Question 4

Which property of water allows it to moderate Earth's climate and support life?

Accepted Answer

High specific heat capacity, due to hydrogen bonding between water molecules: $$q = mc\Delta T$$

Question 5

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange with heads facing water and tails facing inward.

Question 6

A triglyceride is formed by the condensation of which molecules?

Accepted Answer

One glycerol and three fatty acids

Question 7

Which of the following is a correct description of a buffer system in biological fluids?

Accepted Answer

A buffer system resists changes in pH by neutralizing added acids or bases, often involving a weak acid and its conjugate base: $$\ce{HA \rightleftharpoons H^+ + A^-}$$

Question 8

Which macromolecule is primarily responsible for storing genetic information in cells?

Accepted Answer

Nucleic acids (DNA and RNA)

Question 9

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

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 10

Which of the following is the correct order of levels of organization in living systems, from smallest to largest?

Accepted Answer

Atom $$\rightarrow$$ Molecule $$\rightarrow$$ Organelle $$\rightarrow$$ Cell $$\rightarrow$$ Tissue $$\rightarrow$$ Organ $$\rightarrow$$ Organ system $$\rightarrow$$ Organism $$\rightarrow$$ Population $$\rightarrow$$ Community $$\rightarrow$$ Ecosystem $$\rightarrow$$ Biosphere

Question 11

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of chemical reactions, increasing the rate of reaction.

Question 12

A solution has a pH of 2. Which of the following best describes its properties?

Accepted Answer

It is strongly acidic, with a high concentration of $$\ce{H^+}$$ ions.

Question 13

Which of the following is a correct example of a hydrolysis reaction?

Accepted Answer

Breaking a polysaccharide into monosaccharides by adding water: $$\ce{(C6H10O5)_n + nH2O \rightarrow nC6H12O6}$$

Question 14

Which of the following best explains why buffers are important in biological systems?

Accepted Answer

Buffers maintain a stable pH, which is crucial for enzyme activity and cellular processes.

Question 15

Which of the following is a correct description of the primary structure of a protein?

Accepted Answer

The sequence of amino acids in a polypeptide chain.

Question 16

Which of the following is a correct statement about the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Question 17

A student observes that the average distance between slugs in a plot increases during the day and decreases at night. Which hypothesis best explains this pattern?

Accepted Answer

Slugs are more active and spread out during the day to avoid competition for resources.

Question 18

Which of the following is a correct description of the role of ATP in cells?

Accepted Answer

ATP stores and provides energy for cellular processes by releasing a phosphate group: $$\ce{ATP \rightarrow ADP + P_i}$$

Question 19

Which of the following best describes the difference between a monosaccharide and a polysaccharide?

Accepted Answer

A monosaccharide is a single sugar unit, while a polysaccharide is composed of many sugar units linked together.

General Biology Study Guide: Organization, Chemistry, Macromolecules, and Experimental Design

Guida di studio - Domande di pratica

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