Question 1

Water molecules are held together by ionic bonds. True or False?

Accepted Answer

A) True 
 B)False

Question 2

If sulfur has an atomic number of 16, how many covalent bonds does it form?

Accepted Answer

A) 0 
B) 2 
C) 4 
D) 6 
E) 8 
A) 0 
B) 2 
C) 4 
D) 6 
E) 8

Question 3

Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to determine the age of items. Carbon-14 contains six protons and eight neutrons. During the process of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which of the following is the BEST explanation of what has occurred?

Accepted Answer

A) The resulting atom still has an unstable nucleus. 
B) The resulting atom is now a different element because the number of protons has changed. 
C) The resulting atom is still carbon-14. 
D) An ionic bond has formed. 
A) The resulting atom still has an unstable nucleus. 
B) The resulting atom is now a different element because the number of protons has changed. 
C) The resulting atom is still carbon-14. 
D) An ionic bond has formed.

Question 4

What property of water, in which water molecules stick to each other, is responsible for the ability of plants to get water from their roots up to their leaves?

Accepted Answer

The answer of What property of water, in which water...

Question 5

A buffer is essential in living systems to maintain a constant pH. True or False?

Accepted Answer

A) True 
 B)False

Question 6

The second electron shell is considered to be full when it contains ________ electrons.

Accepted Answer

The answer of The second electron shell is considered to...

Question 7

Sweating is a useful cooling mechanism for humans because water:

Accepted Answer

A) takes up a great deal of heat in changing from its liquid state to its gaseous state. 
B) takes up a great deal of heat in changing from its solid state to its liquid state. 
C) can exist in two states at temperatures common on Earth. 
D) is an outstanding solvent. 
E) ionizes readily. 
A) takes up a great deal of heat in changing from its liquid state to its gaseous state. 
B) takes up a great deal of heat in changing from its solid state to its liquid state. 
C) can exist in two states at temperatures common on Earth. 
D) is an outstanding solvent. 
E) ionizes readily.

Question 8

Which of the following best explains the attraction of water molecules to each other?

Accepted Answer

A) nonpolar covalent bond 
B) polar covalent bond 
C) ionic bond 
D) hydrogen bond 
E) electronproton interaction 
A) nonpolar covalent bond 
B) polar covalent bond 
C) ionic bond 
D) hydrogen bond 
E) electronproton interaction

Question 9

The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2)EXCEPT that it:

Accepted Answer

A) is stable. 
B) is covalently bonded. 
C) shares one pair of electrons. 
D) is polar. 
A) is stable. 
B) is covalently bonded. 
C) shares one pair of electrons. 
D) is polar.

Question 10

Iron is an important element in human body cells. If iron has an atomic number of 26, what does this tell you about this element?

Accepted Answer

A) An iron atom has 13 electrons and 13 protons. 
B) An iron atom has 13 protons and 13 neutrons. 
C) An iron atom has 26 protons. 
D) An iron atom is unable to become an isotope. 
A) An iron atom has 13 electrons and 13 protons. 
B) An iron atom has 13 protons and 13 neutrons. 
C) An iron atom has 26 protons. 
D) An iron atom is unable to become an isotope.

Question 11

Most liquids become less dense upon solidification, but water is different in that it becomes more dense when it solidifies. True or False?

Accepted Answer

A) True 
 B)False

Question 12

Every atom has an equal number of electrons and protons. True or False?

Accepted Answer

A) True 
 B)False

Question 13

Carbon has atomic number 6. Carbon most likely:

Accepted Answer

A) shares electrons. 
B) gains electrons. 
C) loses electrons. 
D) shares protons. 
E) loses protons. 
A) shares electrons. 
B) gains electrons. 
C) loses electrons. 
D) shares protons. 
E) loses protons.

Question 14

When the acidic level of human blood increases, how is homeostasis maintained?

Accepted Answer

A) Bicarbonate (HCO3-)releases H+ ions that combine with excess OH- ions to form H2O. 
B) H+ ion-donor levels increase. 
C) Bicarbonate (HCO3-)accepts H+ ions and forms carbonic acid. 
D) Carbonic acid eats up the extra OH- ions. 
A) Bicarbonate (HCO3-)releases H+ ions that combine with excess OH- ions to form H2O. 
B) H+ ion-donor levels increase. 
C) Bicarbonate (HCO3-)accepts H+ ions and forms carbonic acid. 
D) Carbonic acid eats up the extra OH- ions.

Question 15

What determines the cohesiveness of water molecules?

Accepted Answer

A) hydrogen bonds 
B) ionic bonds 
C) covalent bonds 
D) hydrophobic interactions 
A) hydrogen bonds 
B) ionic bonds 
C) covalent bonds 
D) hydrophobic interactions

Question 16

Radioactive isotopes are biological tools that are often used to:

Accepted Answer

A) measure the size of fossils. 
B) detect brain tumors. 
C) build up a store of calcium in a cell. 
D) increase the pH of blood. 
A) measure the size of fossils. 
B) detect brain tumors. 
C) build up a store of calcium in a cell. 
D) increase the pH of blood.

Question 17

Unlike a rock, a reptile can sit in the hot sunshine without its body temperature soaring quickly. This is because the water in its body:

Accepted Answer

A) has a high specific heat. 
B) has a low specific heat. 
C) is a good solvent. 
D) is a poor solvent. 
A) has a high specific heat. 
B) has a low specific heat. 
C) is a good solvent. 
D) is a poor solvent.

Question 18

The hydrogen bond between two water molecules forms because water is:

Accepted Answer

A) polar. 
B) nonpolar. 
C) a liquid. 
D) a small molecule. 
E) hydrophobic. 
A) polar. 
B) nonpolar. 
C) a liquid. 
D) a small molecule. 
E) hydrophobic.

Question 19

Hydrophilic molecules:

Accepted Answer

A) form hydrogen bonds among themselves. 
B) are neutral and nonpolar. 
C) readily dissolve in water. 
D) do not readily dissolve in water. 
E) are repelled by water. 
A) form hydrogen bonds among themselves. 
B) are neutral and nonpolar. 
C) readily dissolve in water. 
D) do not readily dissolve in water. 
E) are repelled by water.

Question 20

If you place a paper towel in a dish of water, the water will:

Accepted Answer

A) separate into H+ and OH- ions, which will react with the paper towel molecules. 
B) dissolve the towel because water is a good solvent. 
C) move away from the towel because water molecules have hydrophobic interactions. 
D) move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other. 
E) move up the towel because water molecules move quickly as it vaporizes. 
A) separate into H+ and OH- ions, which will react with the paper towel molecules. 
B) dissolve the towel because water is a good solvent. 
C) move away from the towel because water molecules have hydrophobic interactions. 
D) move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other. 
E) move up the towel because water molecules move quickly as it vaporizes.

Exam 2: Atoms, Molecules, and Life

Water molecules are held together by ionic bonds. True or False?

If sulfur has an atomic number of 16, how many covalent bonds does it form?

What property of water, in which water molecules stick to each other, is responsible for the ability of plants to get water from their roots up to their leaves?

A buffer is essential in living systems to maintain a constant pH. True or False?

The second electron shell is considered to be full when it contains ________ electrons.

Sweating is a useful cooling mechanism for humans because water:

Which of the following best explains the attraction of water molecules to each other?

The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2)EXCEPT that it:

Iron is an important element in human body cells. If iron has an atomic number of 26, what does this tell you about this element?

Most liquids become less dense upon solidification, but water is different in that it becomes more dense when it solidifies. True or False?

Every atom has an equal number of electrons and protons. True or False?

Carbon has atomic number 6. Carbon most likely:

When the acidic level of human blood increases, how is homeostasis maintained?

What determines the cohesiveness of water molecules?

Radioactive isotopes are biological tools that are often used to:

Unlike a rock, a reptile can sit in the hot sunshine without its body temperature soaring quickly. This is because the water in its body:

The hydrogen bond between two water molecules forms because water is:

Hydrophilic molecules:

If you place a paper towel in a dish of water, the water will:

An Introduction to Life on Earth

Biological Molecules

Cell Structure and Function

Cell Membrane Structure and Function

Energy Flow in the Life of a Cell

Capturing Solar Energy: Photosynthesis

Harvesting Energy: Glycolysis and Cellular Respiration

The Continuity of Life: Cellular Reproduction

Patterns of Inheritance

Dna: the Molecule of Heredity

Gene Expression and Regulation

Biotechnology

Principles of Evolution

How Populations Evolve

The Origin of Species

The History of Life

Systematics: Seeking Order Amidst Diversity

The Diversity of Prokaryotes and Viruses

The Diversity of Protists

The Diversity of Plants

The Diversity of Fungi

Animal Diversity I: Invertebrates

Animal Diversity Ii: Vertebrates

Animal Behavior

Population Growth and Regulation

Community Interactions

How Do Ecosystems Work

Earths Diverse Ecosystems

Conserving Earths Biodiversity

Homeostasis and the Organization of the Animal Body

Circulation

Respiration

Nutrition and Digestion

The Urinary System

Defenses Against Disease

Chemical Control of the Animal Body: the Endocrine System

The Nervous System

The Senses

Action and Support: the Muscles and Skeleton

Animal Reproduction

Animal Development

Plant Anatomy and Nutrient Transport

Plant Reproduction and Development

Plant Responses to the Environment

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