Student Solution Manual OpenStax Biology 2nd Edition
Table of Contents
Chapter 1 ....................................................................................................................................................................... 2
Chapter 2 ....................................................................................................................................................................... 2
Chapter 4 ....................................................................................................................................................................... 4
Chapter 5 ....................................................................................................................................................................... 6
Chapter 6 ....................................................................................................................................................................... 7
Chapter 7 ....................................................................................................................................................................... 8
Chapter 8 ....................................................................................................................................................................... 9
Chapter 9 ..................................................................................................................................................................... 10
Chapter 10 ................................................................................................................................................................... 11
Chapter 11 ................................................................................................................................................................... 13
Chapter 12 ................................................................................................................................................................... 14
Chapter 13 ................................................................................................................................................................... 15
Chapter 14 ................................................................................................................................................................... 15
Chapter 15 ................................................................................................................................................................... 17
Chapter 16 ................................................................................................................................................................... 18
Chapter 17 ................................................................................................................................................................... 19
Chapter 18 ................................................................................................................................................................... 20
Chapter 19 ................................................................................................................................................................... 21
Chapter 20 ................................................................................................................................................................... 22
Chapter 21 ................................................................................................................................................................... 22
Chapter 22 ................................................................................................................................................................... 23
Chapter 23 ................................................................................................................................................................... 25
Chapter 24 ................................................................................................................................................................... 26
Chapter 25 ................................................................................................................................................................... 27
Chapter 26 ................................................................................................................................................................... 28
Chapter 27 ................................................................................................................................................................... 28
Chapter 28 ................................................................................................................................................................... 30
Chapter 29 ................................................................................................................................................................... 31
Chapter 30 ................................................................................................................................................................... 32
Chapter 31 ................................................................................................................................................................... 33
Chapter 32 ................................................................................................................................................................... 34
Chapter 33 ................................................................................................................................................................... 35
Chapter 34 ................................................................................................................................................................... 36
Chapter 35 ................................................................................................................................................................... 37
Chapter 36 ................................................................................................................................................................... 39
Chapter 37 ................................................................................................................................................................... 40
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,Chapter 38 ................................................................................................................................................................... 41
Chapter 39 ................................................................................................................................................................... 42
Chapter 40 ................................................................................................................................................................... 43
Chapter 41 ................................................................................................................................................................... 44
Chapter 42 ................................................................................................................................................................... 45
Chapter 43 ................................................................................................................................................................... 46
Chapter 44 ................................................................................................................................................................... 47
Chapter 45 ................................................................................................................................................................... 48
Chapter 46 ................................................................................................................................................................... 50
Chapter 47 ................................................................................................................................................................... 51
Chapter 1
1 Figure 1.6 1: C; 2: F; 3: A; 4: B; 5: D; 6: E. The original hypothesis is incorrect, as the coffeemaker
works when plugged into the outlet. Alternative hypotheses include that the toaster might be broken
or that the toaster wasn't turned on.
3 Figure 1.16 Communities exist within populations which exist within ecosystems.
4B
6D
8C
10 C
12 B
14 D
16 Answers will vary, but should apply the steps of the scientific method. One possibility could be a
car which doesn’t start. The hypothesis could be that the car doesn’t start because the battery is
dead. The experiment would be to change the battery or to charge the battery and then check whether
the car starts or not. If it starts, the problem was due to the battery, and the hypothesis is accepted.
18 Answers will vary. Topics that fall inside the area of biological study include how diseases affect
human bodies, how pollution impacts a species’ habitat, and how plants respond to their
environments. Topics that fall outside of biology (the “study of life”) include how metamorphic rock
is formed and how planetary orbits function.
20 Answers will vary. Layers of sedimentary rock have order but are not alive. Technology is capable
of regulation but is not, of itself, alive.
22 During your walk, you may begin to perspire, which cools your body and helps your body to
maintain a constant internal temperature. You might also become thirsty and pause long enough
for a cool drink, which will help to restore the water lost during perspiration.
Chapter 2
1 Figure 2.3 Carbon-12 has six neutrons. Carbon-13 has seven neutrons.
3. Figure 2.24 C
3 A
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, 6 C
8 D
10C
12 D
14 Ionic bonds are created between ions. The electrons are not shared between the atoms, but rather
are associated more with one ion than the other. Ionic bonds are strong bonds, but are weaker than
covalent bonds, meaning it takes less energy to break an ionic bond compared with a covalent one.
16 Buffers absorb the free hydrogen ions and hydroxide ions that result from chemical reactions.
Because they can bond these ions, they prevent increases or decreases in pH. An example of a buffer
system is the bicarbonate system in the human body. This system is able to absorb hydrogen and
hydroxide ions to prevent changes in pH and keep cells functioning properly.
18 Carbon is unique and found in all living things because it can form up to four covalent bonds
between atoms or molecules. These can be nonpolar or polar covalent bonds, and they allow for
the formation of long chains ofcarbon molecules that combine to form proteins and DNA.
Chapter 3
1 Figure 3.5 Glucose and galactose are aldoses. Fructose is a ketose.
3 Figure 3.33 Adenine is larger than cytosine and will not be able to base pair properly with the
guanine on the opposing strand. This will cause the DNA to bulge. DNA repair enzymes may
recognize the bulge and replace the incorrect nucleotide.
4C
6A
8D
10 B
12 D
14 C
16 B
18 C
20 C
21 Biological macromolecules are organic because they contain carbon.
23 Amino acids can be linked into long chains through condensation reactions. One of the hydrogen
atoms bonded to the nitrogen atom of an amino acid reacts with the –OH group attached to the
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, terminal carbon on another amino acid. Since both ends of the molecule can participate in
condensation reactions, peptide bonds can be made in both directions to create a long amino acid
chain.
25 The β 1-4 glycosidic linkage in cellulose cannot be broken down by human digestive enzymes.
Herbivores such as cows, koalas, and buffalos are able to digest grass that is rich in cellulose and use
it as a food source because bacteria and protists in their digestive systems, especially in the rumen,
secrete the enzyme cellulase. Cellulases can break down cellulose into glucose monomers that can
be used as an energy source by the animal.
27 Fat serves as a valuable way for animals to store energy. It can also provide insulation. Waxes can
protect plant leaves and mammalian fur from getting wet. Phospholipids and steroids are important
components of animal cell membranes, as well as plant, fungal, and bacterial membranes.
29 Fats have a higher energy density than carbohydrates (averaging 9kcal/gram versus 4.3kcal/gram
respectively). Thus, on a per gram basis, more energy can be stored in fats than can be stored in
carbohydrates. Additionally, fats are packaged into spherical globules to minimize interactions with
the water-based plasma membrane, while glycogen is a large branched carbohydrate that cannot be
compacted for storage.
31 A change in gene sequence can lead to a different amino acid being added to a polypeptide
chain instead of the normal one. This causes a change in protein structure and function. For
example, in sickle cell anemia, the hemoglobin β chain has a single amino acid substitution—the
amino acid glutamic acid in position six is substituted by valine. Because of this change,
hemoglobin molecules form aggregates, and the disc-shaped red blood cells assume a crescent shape,
which results in serious health problems.
33 The protein must form a channel in the plasma membrane that allows water into the cell since
water cannot cross the plasma membrane by itself. Since aquaporins are embedded in the plasma
membrane and connect with both the intracellular and extracellular spaces, it must be amphipathic
like the plasma membrane. The top and bottom of the protein must contain charged or polar amino
acids (hydrophilic) to interact with the aqueous environments. The exterior transmembrane region
must contain non-polar amino acids (hydrophobic) that can interact with the phospholipid tail.
However, the inside of this channel must contain hydrophilic amino acids since they will interact
with the traveling water molecules.
35 The four types of RNA are messenger RNA, ribosomal RNA, transfer RNA, and microRNA.
Messenger RNA carries the information from the DNA that controls all cellular activities. The
mRNA binds to the ribosomes that are constructed of proteins and rRNA, and tRNA transfers the
correct amino acid to the site of protein synthesis. microRNA regulates the availability of mRNA for
translation.
Chapter 4
1 Figure 4.7 Substances can diffuse more quickly through small cells. Small cells have no need for
organelles and therefore do not need to expend energy getting substances across organelle
membranes. Large cells have organelles that can separate cellular processes, enabling them to build
molecules that are more complex.
3 Figure 4.18 It would end up on the outside. After the vesicle passes through the Golgi apparatus
and fuses with the plasma membrane, it turns inside out.
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