$$\text{Mass Number} = \text{Number of Protons} + \text{Number of Neutrons}$$

Question 1

Which of the following best explains why helium (He) is chemically inert while hydrogen (H) is highly reactive?

Accepted Answer

Helium has a full outer electron shell, making it stable and unlikely to react.

Question 2

Which statement correctly describes the difference between an ionic bond and a covalent bond?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 3

A sodium atom (Na) loses one electron to become Na+. What type of ion is formed and what is its charge?

Accepted Answer

A cation with a +1 charge

Question 4

Which of the following best describes the role of hydrogen bonds in water?

Accepted Answer

They create surface tension and reduce evaporation.

Question 5

Which of the following is the correct formula for calculating the mass number of an atom?

Accepted Answer

$$	ext{Mass Number} = 	ext{Number of Protons} + 	ext{Number of Neutrons}$$

Question 6

A solution has a pH of 5. Which of the following statements is true?

Accepted Answer

The solution is acidic and has a higher concentration of H$$^+$$ ions than pure water.

Question 7

Which of the following best describes the structure of a phospholipid?

Accepted Answer

A molecule with a hydrophilic phosphate head and two hydrophobic fatty acid tails

Question 8

Which of the following is a correct pairing of nucleic acid bases in DNA?

Accepted Answer

Adenine (A) pairs with Thymine (T)

Question 9

Which of the following best explains why glucose is considered a monosaccharide?

Accepted Answer

It contains a single sugar unit and cannot be hydrolyzed into simpler sugars.

Question 10

Which of the following is NOT a function of proteins in the human body?

Accepted Answer

Storing genetic information

Question 11

Which of the following best describes the process of dehydration synthesis?

Accepted Answer

It joins two molecules together by removing a water molecule.

Question 12

Which of the following statements about ATP is correct?

Accepted Answer

ATP stores energy in the bonds between its phosphate groups.

Question 13

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

Accepted Answer

Saturated fatty acids have only single bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 14

A patient’s blood pH is measured at 7.2. Which condition does this indicate, and what is a possible consequence?

Accepted Answer

Acidosis; the patient may fall into a coma if the pH drops further.

Question 15

Which of the following best describes 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 real-life example of a chemical reaction important for human physiology?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O ($$formation of water from hydrogen and oxygen)

Question 17

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water is a polar molecule, allowing it to surround and separate ions.

Question 18

Which of the following is a function of cholesterol in the human body?

Accepted Answer

It is needed for cell membrane repair and hormone synthesis.

Question 19

Which of the following best describes the process of hydrolysis?

Accepted Answer

It breaks down complex molecules by adding a water molecule.

Chapter 2: The Chemical Level of Organization – Study Notes for Anatomy & Physiology I

Study Guide - Practice Questions