Exam 1

Question 1

In his article on mosquitoes, “Little Things That Go Buzzzzz in the Night,” published in the August 2005 issue of Wildlife in North Carolina, NCSU Professor of Entomology, Dr. Clyde Sorenson, said the following:
“…Clearly, from our own intensely personal viewpoint, mosquitoes can’t be much good – they bite and they transmit diseases. Ecologically, though, they do have value. The larvae can be prey for other animals, and some species are important pollinators (male mosquitoes only feed on plant nectar or sap, and females also drink nectar). More difficult to accept, but probably more importantly, mosquitoes vector, or transmit, diseases to many species of animals in addition to us. While it is certainly an unfortunate outcome for the individual animals infected, these diseases are important in regulating wildlife populations, just as predators are. So mosquitoes do have an important role to play in the web of life, although we have a hard time viewing their position positively.”
How does this quote illustrate the perspective of ecology as a science?
A) This quote illustrates how ecologists, as scientists, attempt to be value-neutral, withholding judgment about whether a particular situation or action is good or bad, viewing that situation solely on its ecological merits.
B) This quote illustrates how ecologists, as scientists, adopt a human perspective, taking into account human social, religious, moral, economic and other interests, judging any particular situation as good or bad.

Answer 1

A) This quote illustrates how ecologists, as scientists, attempt to be value-neutral, withholding judgment about whether a particular situation or action is good or bad, viewing that situation solely on its ecological merits.

Question 2

The PMB 360 students are all in perfect health, maintaining an internal body temperature of 98.6 oF. The classroom in which they are sitting has an air temperature of 75.0 oF. Which of the following principles is illustrated by the situation just described?
A) Ecological systems exist in a dynamic steady state in balance with their physical environment.
B) Ecological systems exist in a dynamic steady state out of balance with their physical environment.

Answer 2

B) Ecological systems exist in a dynamic steady state out of balance with their physical environment

Question 3

Bony fish of freshwater habitats are hyper-osmotic, living in a watery medium that has lower salt concentration than their bodies. As a consequence, these animals have to contend with which of the following?
A) replacing water lost to the surrounding medium while eliminating excess salts
B) retaining salts while eliminating excess water absorbed from the surrounding medium

Answer 3

B) retaining salts while eliminating excess water absorbed from the surrounding medium

Question 4

Marine species of sharks and rays have a unique way of raising the osmotic potential of their blood to that of the surrounding seawater. What is this mechanism?
A) retention of urea in the bloodstream
B) retention of sodium chloride in the bloodstream
C) retention of small carbohydrate molecules in their bloodstream
D) all of the above

Answer 4

A) retention of urea in the bloodstream

Question 5

Why is the enzyme RuBP carboxylase-oxidase (Rubisco) so important in photosynthetic assimilation of carbon?
A) This enzyme is responsible for the conversion of organic acids into glucose.
B) This enzyme is responsible for the conversion of energy contained in light into energy stored in ATP and NADPH.
C) This enzyme is responsible for the conversion of glucose into sucrose.
D) This enzyme is responsible for the incorporation of carbon (from the atmosphere or water) into an organic compound (glyceraldehyde 3-phosphate or G3P) available for Calvin-Benson cycle synthesis of glucose.

Answer 5

D) This enzyme is responsible for the incorporation of carbon (from the atmosphere or water) into an organic compound (glyceraldehyde 3-phosphate or G3P) available for Calvin-Benson cycle synthesis of glucose.

Question 6

Which of the following statements about C4 plants is false?
A) C4 plants physically separate the first step of photosynthetic carbon assimilation (in mesophyll cells) from the other steps of photosynthesis (in bundle sheath cells).
B) The first chemical product of photosynthetic carbon fixation in C4 plants is glyceraldehyde 3-phosphate (G3P), a 3-carbon molecule.

Answer 6

B) The first chemical product of photosynthetic carbon fixation in C4 plants is glyceraldehyde 3-phosphate (G3P), a 3-carbon molecule.

Question 7

One of the challenges of being a land plant with leaves is that stomates must be open in order for the plant to obtain CO2 required for photosynthesis, but water also evaporates from the plant via the same stomatal openings. Why is this situation so problematic for plants of warm, dry environments?
A) The tendency of water to exit the leaf far exceeds the tendency of CO2 to enter the leaf, resulting in excessive water loss.
B) The tendency of CO2 to enter the leaf far exceeds the tendency of water to exit the leaf, resulting in CO2 overloading.

Answer 7

A) The tendency of water to exit the leaf far exceeds the tendency of CO2 to enter the leaf, resulting in excessive water loss.

Question 8

Kangaroo rats are nocturnal, and black-capped chickadees are diurnal. Both are seed-eaters. Which aspect of these animals’ ecological relationships is represented by information about activity periods and food requirements?
A) their habitats B) their niches

Answer 8

B) their niches

Question 9

Which of the following must exist for there to be evolution by natural selection?
A) variation among individuals
B) inheritance of that variation
C) differences in survival and reproductive success, or fitness, related to that variation
D) all of the above

Answer 9

D) all of the above

Question 10

A well-known breeder of leopard geckos has been breeding for a mutation on a gene that controls body size. Homozygotes for the mutant allele (we’ll call these GG) are very large (called Super Giants), normal homozygotes (we’ll call these gg) exhibit normal size, and heterozygotes (Gg), called Giants, are intermediate between the Super Giants and normal animals.
The breeder has a large population of animals of known genotype. He would like to determine whether or not Super Giants differ in mean body mass when compared to Giants. He selects at random 10 Super Giant males and 10 Giant males from his breeding population. All animals are about 1 year old and have been maintained under the same conditions. He weighs the animals and compares the results, as seen in the graph below.
Given his interest in evaluating differences in body mass between his two populations (Giants and Super Giants), what will his null hypothesis be?
A) There is no difference in mean body mass between Giants and Super Giants.
B) Giants have a lower mean body mass than Super Giants.
C) Giants have a higher mean body mass than Super Giants.
D) Giants and Super Giants differ in mean body mass.

Answer 10

A) There is no difference in mean body mass between Giants and Super Giants.

Question 11

Given his choice of null hypothesis, which of the remaining choices from question 10 (above) would be the most appropriate alternative hypothesis?
Given his interest in evaluating differences in body mass between his two populations (Giants and Super Giants), what will his null hypothesis be?
A) There is no difference in mean body mass between Giants and Super Giants.
B) Giants have a lower mean body mass than Super Giants.
C) Giants have a higher mean body mass than Super Giants.
D) Giants and Super Giants differ in mean body mass.

Answer 11

D) Giants and Super Giants differ in mean body mass

Question 12

Before performing a statistical analysis (t-test), he guesses the approximate probability of being wrong if he concludes that Giants and Super Giants differ in mean body mass. What is a reasonable guess about this probability, given the results in the figure above?
A) p = 1.05
B) p = 1.0
C) p = 0.04
D) p = 0.0

Answer 12

C) p = 0.04

Question 13

After performing a t-test, he finds that the actual probability of being wrong if he concludes that Giants and Super Giants differ in mean body mass is 0.02. He may now:
A) fail to reject the null hypothesis
B) reject the null hypothesis
C) neither of the above

Answer 13

B) reject the null hypothesis

Question 14

What is the policy regarding hour exams in BIO/PB 360 this fall?
A) There are four hour exams scheduled. However, only three exams will count toward your semester grade. We will drop your lowest score of the four.
B) There are four hour exams scheduled. All four exams count toward your semester grade.

Answer 14

A) There are four hour exams scheduled. However, only three exams will count toward your semester grade. We will drop your lowest score of the four.

Question 15

What is the new policy regarding the final exam in BIO/PB 360 this fall?
A) It will count as 30% toward your semester grade.
B) It will count as 15% toward your semester grade.

Answer 15

B) It will count as 15% toward your semester grade.

Question 16

How can ecology best help each of us understand the role of humans in nature?
A) Ecology provides a reference point of unspoiled nature.
B) Ecology provides a set of moral precepts.
C) Ecology provides a political agenda.
D) Ecology provides a scientific understanding of how natural systems work and how humans function as part of the natural world.

Answer 16

D) Ecology provides a scientific understanding of how natural systems work and how humans function as part of the natural world.

Question 17

Who gave the word "ecology" its current broad meaning?
A) the German zoologist Ernst Haeckel
B) the Swedish botanist Carl Linnaeus
C) the English naturalist Charles Darwin
D) the American ecologist Rachel Carson

Answer 17

A) the German zoologist Ernst Haeckel

Question 18

Of the following fields, all except one focus on the application of ecological understanding to solving problems concerning the environment and its inhabitants. Which is the exception?
A) environmental science
B) applied ecology
C) conservation biology
D) ecology

Answer 18

D) ecology

Question 19

Which of the following systems is comprised of local collections of populations together with their physical and chemical environment?
A) organism B) population C) community D) ecosystem E) biosphere

Answer 19

D) ecosystem

Question 20

It may be said that the approach taken by an ecologist to the study of the natural world depends on the level of ecological organization studied. For example, an ecologist who takes the organism approach to the study of ecology (as in our lecture example of the cactus wren) would most likely be interested in:
A) adaptations of individual organisms that suit them for life in their environment.
B) changes in numbers, resulting from births and deaths, of individuals belonging to a particular species in a particular place.
C) the number and relative abundances of various species living in a particular place.
D) activities of organisms as well as physical and chemical transformations of energy and materials in the soil, atmosphere, and water.
E) transport of energy and materials at the global scale.

Answer 20

A) adaptations of individual organisms that suit them for life in their environment.

Question 21

In class, we discussed research being conducted at an experimental watershed at Coweeta, NC. Scientists at Coweeta monitor streamflow to determine fluxes of materials leaving the watershed via this pathway. What level of ecological organization is the focus of their work?
A) organism B) population C) community D) ecosystem E) biosphere

Answer 21

D) ecosystem

Question 22

Because all ecological systems have biological components, they are exempt from the physical constraints that govern other natural systems.
A) True B) False

Answer 22

B) False

Question 23

Marquis and Whelan conducted research on the role of bird predation in reducing the consumption of plants by insect herbivores. Which of the following features did they incorporate into their experiment?
A) controls reproducing all aspects of the experiment except for the variable of interest
B) additional controls for assessing experimental effects
C) replication to ensure that results were repeatable
D) all of the above

Answer 23

D) all of the above

Question 24

Traditional ecological knowledge (or TEK, for short) may be summarized by the following, which in many ways also summarizes the “take-home message” of PB 360:
A) All things are connected.
B) All things are related.
C) both of the above

Answer 24

C) both of the above

Question 25

When a membrane permeable to water separates water of more negative potential on one side of the membrane from water of less negative potential on the other, what will be the tendency of the water molecules?
A) There will be a net diffusion of water molecules across the membrane from the side of more negative potential to the side of less negative potential.
B) There will be a net diffusion of water molecules across the membrane from the side of less negative potential to the side of more negative potential.
C) There will be equal movement of water molecules across the membrane in both directions.
D) There will be no movement of water molecules across the membrane.

Answer 25

B) There will be a net diffusion of water molecules across the membrane from the side of less negative potential to the side of more negative potential.

Question 26

Some algae living at shallow depths in the ocean (the alga Ulva is an example) have photosynthetic pigments much like those of terrestrial plants, absorbing strongly in the red and blue parts of the visible spectrum and reflecting in the green part of the spectrum. However, algae living deeper in the ocean (the red alga Porphyra is an example) have specialized pigments that enable them to absorb __________ light.
A) violet B) orange C) green D) brown E) red

Answer 26

C) green

Question 27

In sea gulls living in cold regions, cold blood returning to the body from extremities (legs and feet) flows in a direction opposite that of warm blood entering the extremities from the body. These opposing flows enable the animal to capture some of the heat contained in blood flowing from the body and return that heat to the body. This kind of circulation has a special name. What is it?
A) countercurrent circulation B) general conditioning
C) inverse processing D) reverse osmosis

Answer 27

A) countercurrent circulation

Question 28

Which of the following represents adaptation(s) of the kangaroo rat to life in a desert environment?
A) gathering water each morning from the dew that forms on leaf surfaces
B) spending daytime hours in a relatively cool, comfortable burrow
C) migrating north during the summer months
D) all of the above

Answer 28

B) spending daytime hours in a relatively cool, comfortable burrow

Question 29

Kangaroo rats can obtain all the water they need from the seeds they eat. Which of the following contributes the majority of the water they obtain from seeds?
A) water absorbed by seeds from the atmosphere
B) water that results from oxidation of proteins, fats, and carbohydrates contained in seeds

Answer 29

B) water that results from oxidation of proteins, fats, and carbohydrates contained in seeds

Question 30

Black-capped chickadees utilize torpor (a voluntary drop in body temperature) as an important adaptation to surviving long, cold winter nights. Why do these tiny birds engage in torpor?
A) If they did not engage in torpor, they would not sleep well, and they would be less efficient at foraging the next day.
B) If they did not engage in torpor, they would be unable to manufacture enzymes that function better at lower temperatures.
C) If they did not engage in torpor, their energy demands would exceed their available energy reserves.
D) If they did not engage in torpor, their relatively high body temperature would make them vulnerable to predators, who can detect infrared radiation emitted by warm birds.

Answer 30

C) If they did not engage in torpor, their energy demands would exceed their available energy reserves.

Question 31

What is the principal chemical reserve that black-capped chickadees depend on for their energy needs during a long winter night?
A) proteins
B) fats
C) carbohydrates
D) all of the above in equal amounts

Answer 31

B) fats

Question 32

It has sometimes been said that “night is the winter of the tropics”. What is meant by this?
A) Differences between night and day temperatures often exceed differences between mean monthly temperatures of winter and summer.
B) Most locations in the tropics experience sub-freezing temperatures at night, but never during the day.
C) Temperature variation in the tropics is unpredictable.

Answer 32

A) Differences between night and day temperatures often exceed differences between mean monthly temperatures of winter and summer.

Question 33

If “night is the winter of the tropics” (previous question), what aspect of phenotypic plasticity do some hummingbirds use to deal with cool nighttime temperatures?
A) They migrate to the Antarctic.
B) They bury themselves in leaf litter on the forest floor to stay warm.
C) They seek the warmer microclimate of large cities.
D) They undergo torpor.

Answer 33

D) They undergo torpor.

Question 34

Why did average beak size increase in individuals of Darwin’s medium ground finch (and their progeny) during a period of severe drought in the Galápagos?
A) Individuals eating the harder seeds available during the drought developed larger beaks and passed this trait on to their offspring.
B) Individuals with larger beaks could eat the harder seeds available during the drought and survived/reproduced better than individuals with smaller beaks.
C) Individuals with larger beaks are always at an advantage.
D) The observed change in beak size was purely the result of chance.

Answer 34

B) Individuals with larger beaks could eat the harder seeds available during the drought and survived/reproduced better than individuals with smaller beaks.

Question 35

The increase in beak size in Darwin’s medium ground finch (previous question) is an example of which of the following kinds of natural selection?
A) stabilizing selection
B) directional selection
C) disruptive selection
D) divergent selection

Answer 35

B) directional selection

Question 36

The change in frequency of melanistic (dark colored) peppered moths as a result of industrialization in England was an example of:
A) stabilizing selection.
B) directional selection.
C) disruptive selection.
D) divergent selection.

Answer 36

B) directional selection.

Question 37

Which of the following research approaches did H.B.D. Kettlewell use in his classic studies of evolution of coloration in English peppered moths?
A) mark-recapture experiments
B) predator observation experiments
C) both of the above

Answer 37

C) both of the above

Question 38

Individual organisms can adapt to changes in their environments in all of the following ways:
A) evolution by natural selection, phenotypic plasticity, acclimatization
B) phenotypic plasticity, acclimatization, irreversible developmental responses
C) evolution by natural selection, acclimatization, irreversible developmental responses
D) evolution by natural selection, phenotypic plasticity, irreversible developmental responses

Answer 38

B) phenotypic plasticity, acclimatization, irreversible developmental responses

Question 39

All of the following are examples of acclimatization except:
A) Water fleas develop a protective helmet and long tail spine in response to the presence of predators.
B) Trout produce different forms of the enzyme acetylcholinesterase in winter and summer.
C) Humans increase the density of red blood cells when they spend time at high elevations.
D) Rabbits grow thicker fur in winter.

Answer 39

A) Water fleas develop a protective helmet and long tail spine in response to the presence of predators.

Question 40

In class (and in our textbook), the African grasshopper, Gastrimargus africanus, is used as an example of an irreversible developmental response. Why do we think that these grasshoppers develop different epidermal coloration at different times of year?
A) Matching coloration alerts fewer competitors when food is discovered.
B) Matching coloration helps them avoid detection by would-be predators.
C) Matching coloration minimizes absorption of solar radiation.
D) Matching coloration makes them more attractive to potential mates.

Answer 40

B) Matching coloration helps them avoid detection by would-be predators.

Question 41

Which of the following was an interesting outcome of the reciprocal transplant experiments carried out by Niewiarowski and Roosenberg on fence lizards (see text Figure 6.20, below)?
A) Native lizards and transplants from New Jersey performed equally well in Nebraska.
B) Nebraska lizards performed equally well in Nebraska and in New Jersey.
C) New Jersey lizards performed about the same in New Jersey and in Nebraska.
D) Each of the above was an interesting outcome of this experiment.

Answer 41

C) New Jersey lizards performed about the same in New Jersey and in Nebraska.

Question 42

Highbush blueberry plants belonging to a particular species grow in a wide range of environments in North Carolina. Plants growing in acidic bogs are slower growing than plants on fertile, better-drained floodplains. In a reciprocal transplant study, plants from a bog were transplanted to a floodplain and plants from a floodplain were transplanted to a bog. The transplants from the bog performed better in the floodplain, but not as well as plants native to the floodplain. The transplants from the floodplain performed more poorly in the bog, about the same as plants native to the bog. What can we conclude from this experiment about the causes of differences in growth rate between the bog and floodplain populations?
A) They are genetically determined.
B) They reflect phenotypic plasticity.
C) Both of the above conclusions are correct.

Answer 42

C) Both of the above conclusions are correct.

Question 43

A reaction norm is:
A. the phenotypic response of a particular individual or population when exposed to different
environments
B. the change in allele frequencies of a population when experiencing natural selection.

Answer 43

A. the phenotypic response of a particular individual or population when exposed to different
environments

Question 44

In the figure above (from Active Learning Exercise #6), we are comparing reaction norms of two
populations of the same species, one (population ) normally found in environment A, and the
other (population ) normally found in environment B. These two populations are involved in a
reciprocal transplant experiment (the arrows indicate transplantation and change in phenotypic
expression, if any). In which of the three cases above (A, B, or C) does the outcome of the
experiment NOT provide evidence for a genotype-environment interaction?
A) A
B) B
C) C

Answer 44

A) A

Question 45

In the figure above, in which of the three cases do we find evidence for BOTH genotypic
differentiation (G) AND variation due to environmental factors (E), also called phenotypic
plasticity?
A) A
B) B
C) C
D) A, B, and C

Answer 45

D) A, B, and C

Question 46

In the illustration above (text Figure 6.16), we see graphs of photosynthetic rate as a function of leaf temperature for three plant species acclimated at high (H) and low (L) temperatures. What process was investigated by these experiments?
A) kin selection B) acclimatization C) irreversible developmental responses

Answer 46

B) acclimatization

Question 47

In the figure above, which of the three species shows that it is adaptable to a wide range of environmental temperatures?
A) Larrea
B) Atriplex
C) Tidestromia

Answer 47

A) Larrea

Question 48

In the past some ecologists may have overlooked evolution in their quest to learn how ecological systems worked. In our SimUText chapter called “Evolution for Ecology,” the authors conclude that “evolution is a process that ecologists cannot afford to ignore.” Why do the authors make this point?
A) The authors really don’t support this assertion in the chapter.
B) Rapid evolution of ecological relevant traits is clearly possible, driven by both natural events and human activities.
C) The authors are evolutionary biologists and probably don’t appreciate the ecological perspective.

Answer 48

B) Rapid evolution of ecological relevant traits is clearly possible, driven by both natural events and human activities.

Question 49

The authors of the SimUText chapter entitled “Evolution for Ecology” promote __________ in the cultivation of cotton when pink bollworm is a potential pest.
A) exclusive use of transgenic (Bollgard) cotton that makes the Bt toxin
B) exclusive use of non-transgenic cotton
C) planting a mix of transgenic and non-transgenic cotton

Answer 49

C) planting a mix of transgenic and non-transgenic cotton

Question 50

The approach advocated by the authors of the SimUText chapter entitled “Evolution for Ecology” (see previous question) is an example of:
A) the rejection of farming practices based on an understanding of ecology and evolution
B) integrated pest management in farming
C) the “spray and pray” approach to farming

Answer 50

B) integrated pest management in farming

Question 51

You find a tick firmly attached to your leg after working in the field during the summer. A few days later you wake up with a fever and other flu-like symptoms. Should you consult a health professional?
A) No, everyone gets the flu now and then. Don’t bother the doctor.
B) Yes, these symptoms could be indicative of a tick-borne illness, like Rocky Mountain Spotted Fever. Check with your doctor.

Answer 51

B) Yes, these symptoms could be indicative of a tick-borne illness, like Rocky Mountain Spotted Fever. Check with your doctor.