Question 1

Which of the following best distinguishes the domain Eukarya from the other two domains of life on a phylogenetic tree?

Accepted Answer

Eukarya have membrane-bound organelles, including a nucleus, while Bacteria and Archaea do not.

Question 2

Which of the following is NOT a defining feature of living organisms?

Accepted Answer

Ability to photosynthesize

Question 3

A scientist proposes a possible explanation for a phenomenon and then designs an experiment to test it. What is this explanation called?

Accepted Answer

A hypothesis

Question 4

Which of the following best describes the relationship between atomic number and mass number for an element?

Accepted Answer

Atomic number is the number of protons; mass number is the sum of protons and neutrons.

Question 5

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

Accepted Answer

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

Question 6

Which of the following molecules is most likely to be nonpolar?

Accepted Answer

A molecule with equal sharing of electrons between atoms of similar electronegativity

Question 7

Which type of interaction is primarily responsible for the secondary structure of proteins?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 8

What is the name of the bond formed between two amino acids during protein synthesis?

Accepted Answer

Peptide bond

Question 9

Which of the following best describes a condensation (dehydration synthesis) reaction?

Accepted Answer

A reaction in which two monomers are joined together with the removal of a water molecule

Question 10

Which of the following is a correct pairing of a nucleic acid and its monomer?

Accepted Answer

DNA and nucleotide

Question 11

Which of the following pieces of information was NOT critical for Watson and Crick in determining the structure of DNA?

Accepted Answer

The sequence of amino acids in hemoglobin

Question 12

Which of the following is a key difference between RNA and DNA?

Accepted Answer

RNA contains ribose sugar, while DNA contains deoxyribose sugar.

Question 13

Which of the following best describes a monosaccharide?

Accepted Answer

A single sugar molecule that cannot be hydrolyzed to a simpler carbohydrate

Question 14

Which of the following is a common naming strategy for carbohydrates?

Accepted Answer

Using the suffix '-ose' to indicate a sugar

Question 15

Which of the following best explains why carbohydrates are considered 'energy-rich' molecules?

Accepted Answer

They have many C-H and C-C bonds that can be oxidized to release energy.

Question 16

Which of the following polysaccharides is used for energy storage in animals?

Accepted Answer

Glycogen

Question 17

A patient is found to have a mutation that prevents the formation of phosphodiester bonds. Which biological molecule would be most directly affected?

Accepted Answer

Nucleic acids

Question 18

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

Accepted Answer

A hypothesis is a testable explanation for a specific observation; a theory is a broad explanation supported by extensive evidence.

Question 19

Which of the following functional groups is found in all amino acids?

Accepted Answer

Amino group $\left( -\mathrm{NH}_2 \right)$ and carboxyl group $\left( -\mathrm{COOH} \right)$

Question 20

Which of the following best describes a hydrolysis reaction?

Accepted Answer

A reaction in which a polymer is broken down into monomers by the addition of water

Unit 1: Introduction and Biological Molecules – Study Guide

Study Guide - Practice Questions