1 What is Plant Biology?
1. It takes a great deal of time to gather enough wild plants to feed a family the year
around. Human populations are much larger now than they were in the past, whereas
populations of wild plants have diminished; any large-scale gathering of wild plants
would disrupt what ecological balances are left. Therefore, although it might be desirable
to return to survival on wild plants, it is not feasible at this time.
2. This is a question with no single answer; it is primarily intended to promote thought.
3. Virtually limitless speculation is possible here. For example: Maybe early peoples
noticed that rubbing certain aromatic leaves on the skin repelled mosquitoes; this could,
in turn, have led them to chew the same leaves for internal ailments, and later to steep the
leaves in water and then drink the liquid. They retained those leaves that appeared to be
efficacious in treatment of ailments and discarded those with deleterious effects.
4. A number of physicians today are excellent amateur botanists, but the thrust of modern
botany is not primarily medicinal. Our society is so structured and demanding of a
physician's time that it is generally not possible for a modern physician to become
professionally adept in both fields, even though it might be desirable.
5. A simple experiment could involve feeding each individual type of mushroom found in
a grassy area to one group of laboratory animals while feeding another group of similar
animals food known to be nontoxic.
,Stern et al: Introductory Plant Biology, 13
(Instructor Answers to End-of-Chapter Review Questions)
Chapter 1
1. Humans have drained wetlands, cleared vegetation, dumped pollutants into water supplies, and
killed pests and pathogens with chemicals.
2. The scientific method is a series of steps that involves asking a question, formulating a
hypothesis, carrying out experiments, and developing a theory.
3. Plants remove carbon dioxide from the air, produce oxygen, and provide food.
4. Hypotheses are unproven explanations for observations. A control is used in an experiment to
compare to the variable.
5. Plant systematics is the oldest branch of botany. It began when people started to name plants
and to observe natural groupings and relationships among plants.
6. Plant physiology is the study of plant function; plant geography is the study of plant
distribution; plant ecology is the study of the interactions of plants with each other and with their
environment; plant morphology is the study of plant form and life cycles; plant genetics deals
with inheritance; plant cell biology is the study of cell structure and function; economic botany
and ethnobotany focus on human uses of plants and plant products.
,2 The Nature of Life
1. Yes. Some cells, particularly those that function in strengthening or support, lose their
protoplasm as soon as they mature but are still essential to the normal function of an
organism. (Note: Cells have not been discussed in detail at this point in the text, but a
general discussion of the topic is nevertheless possible.)
2. Genetics has not been discussed at this juncture, but consideration of the topic in a
general way is feasible. Even without a knowledge of genetic mechanisms, for example,
students can appreciate the difference between a natural dwarf tree and one that has been
pruned to resemble a dwarf.
3. One would assume that all metabolic activities would be much slower.
, Stern et al: Introductory Plant Biology, 13e
(Instructor Answers to End-of-Chapter Review Questions)
Chapter 2
1. A living organism is composed of cells that contain DNA and a complex set of molecules, is
capable of growth and reproduction, responds to stimuli, carries out metabolism, and can move
and adapt to its environment.
2. Organic molecules contain backbones of carbon atoms.
3. Acids release hydrogen ions when dissolved in water, bases release hydroxyl ions when
dissolved in water and when an acid is combined with a base, a salt and water form.
4. Carbohydrates contain C, H, and O in a ratio of 1:2:1. Lipids do not contain polarized
components, so they are insoluble in water. They contain C, H, and O, but have proportionately
less O than carbohydrates. Proteins consist of C, H, O, and N, and sometimes S. They are
composed of polypeptide chains.
5. Energy is the ability to do work or produce a change in motion or matter. Forms of energy
include kinetic and potential energy.
6. Polymers are formed when two or more subunits called monomers are combined.
7. A protein molecule is composed of subunits called amino acids. A nucleic acid is composed
of subunits called nucleotides.
1. It takes a great deal of time to gather enough wild plants to feed a family the year
around. Human populations are much larger now than they were in the past, whereas
populations of wild plants have diminished; any large-scale gathering of wild plants
would disrupt what ecological balances are left. Therefore, although it might be desirable
to return to survival on wild plants, it is not feasible at this time.
2. This is a question with no single answer; it is primarily intended to promote thought.
3. Virtually limitless speculation is possible here. For example: Maybe early peoples
noticed that rubbing certain aromatic leaves on the skin repelled mosquitoes; this could,
in turn, have led them to chew the same leaves for internal ailments, and later to steep the
leaves in water and then drink the liquid. They retained those leaves that appeared to be
efficacious in treatment of ailments and discarded those with deleterious effects.
4. A number of physicians today are excellent amateur botanists, but the thrust of modern
botany is not primarily medicinal. Our society is so structured and demanding of a
physician's time that it is generally not possible for a modern physician to become
professionally adept in both fields, even though it might be desirable.
5. A simple experiment could involve feeding each individual type of mushroom found in
a grassy area to one group of laboratory animals while feeding another group of similar
animals food known to be nontoxic.
,Stern et al: Introductory Plant Biology, 13
(Instructor Answers to End-of-Chapter Review Questions)
Chapter 1
1. Humans have drained wetlands, cleared vegetation, dumped pollutants into water supplies, and
killed pests and pathogens with chemicals.
2. The scientific method is a series of steps that involves asking a question, formulating a
hypothesis, carrying out experiments, and developing a theory.
3. Plants remove carbon dioxide from the air, produce oxygen, and provide food.
4. Hypotheses are unproven explanations for observations. A control is used in an experiment to
compare to the variable.
5. Plant systematics is the oldest branch of botany. It began when people started to name plants
and to observe natural groupings and relationships among plants.
6. Plant physiology is the study of plant function; plant geography is the study of plant
distribution; plant ecology is the study of the interactions of plants with each other and with their
environment; plant morphology is the study of plant form and life cycles; plant genetics deals
with inheritance; plant cell biology is the study of cell structure and function; economic botany
and ethnobotany focus on human uses of plants and plant products.
,2 The Nature of Life
1. Yes. Some cells, particularly those that function in strengthening or support, lose their
protoplasm as soon as they mature but are still essential to the normal function of an
organism. (Note: Cells have not been discussed in detail at this point in the text, but a
general discussion of the topic is nevertheless possible.)
2. Genetics has not been discussed at this juncture, but consideration of the topic in a
general way is feasible. Even without a knowledge of genetic mechanisms, for example,
students can appreciate the difference between a natural dwarf tree and one that has been
pruned to resemble a dwarf.
3. One would assume that all metabolic activities would be much slower.
, Stern et al: Introductory Plant Biology, 13e
(Instructor Answers to End-of-Chapter Review Questions)
Chapter 2
1. A living organism is composed of cells that contain DNA and a complex set of molecules, is
capable of growth and reproduction, responds to stimuli, carries out metabolism, and can move
and adapt to its environment.
2. Organic molecules contain backbones of carbon atoms.
3. Acids release hydrogen ions when dissolved in water, bases release hydroxyl ions when
dissolved in water and when an acid is combined with a base, a salt and water form.
4. Carbohydrates contain C, H, and O in a ratio of 1:2:1. Lipids do not contain polarized
components, so they are insoluble in water. They contain C, H, and O, but have proportionately
less O than carbohydrates. Proteins consist of C, H, O, and N, and sometimes S. They are
composed of polypeptide chains.
5. Energy is the ability to do work or produce a change in motion or matter. Forms of energy
include kinetic and potential energy.
6. Polymers are formed when two or more subunits called monomers are combined.
7. A protein molecule is composed of subunits called amino acids. A nucleic acid is composed
of subunits called nucleotides.
