Question 1

Which of the following best describes an emergent property in biological systems?

Accepted Answer

A property that arises only when individual components interact in a complex system.

Question 2

Which four elements make up approximately 96% of living matter in organisms?

Accepted Answer

Carbon, hydrogen, oxygen, nitrogen

Question 3

Which term describes the number of protons in the nucleus of an atom?

Accepted Answer

Atomic number

Question 4

Radioactive isotopes are useful in biological research because:

Accepted Answer

They can be used to trace the movement of substances within organisms.

Question 5

Which equation correctly represents the conservation of mass in a chemical reaction?

Accepted Answer

$$\sum \mathrm{mass}_{\mathrm{reactants}} = \sum \mathrm{mass}_{\mathrm{products}}$$

Question 6

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons.

Question 7

What type of bond is formed when electrons are transferred from one atom to another?

Accepted Answer

Ionic bond

Question 8

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons determine the chemical reactivity of an atom.

Question 9

A molecule of methane ($$\mathrm{CH}_4) $$has which type of bond between carbon and hydrogen?

Accepted Answer

Covalent bond

Question 10

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 11

Which type of interaction is responsible for the temporary attraction between molecules due to fluctuating electron distributions?

Accepted Answer

Van der Waals interaction

Question 12

Which of the following is true about chemical equilibrium?

Accepted Answer

The forward and reverse reaction rates are equal.

Question 13

Which equation represents a reversible chemical reaction?

Accepted Answer

$$\mathrm{A} + \mathrm{B} \rightleftharpoons \mathrm{C} + \mathrm{D}$$

Question 14

Which of the following best explains why molecular shape is important in biological systems?

Accepted Answer

Molecular shape affects how molecules interact with biological receptors.

Question 15

Which of the following statements about matter in chemical reactions is correct?

Accepted Answer

Matter is conserved; it cannot be created or destroyed.

Question 16

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 17

Which of the following bonds is generally strongest in biological systems?

Accepted Answer

Covalent bond

Question 18

Which of the following is NOT a product of photosynthesis?

Accepted Answer

Carbon dioxide

Question 19

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 8, Mass number: 16

Question 20

Which of the following best describes a chemical reaction?

Accepted Answer

A process in which atoms are rearranged to form new substances.

General biology unit 2

Study Guide - Practice Questions