Cumulative 2

Question 1

Which statement best describes what ultimately happens to the chemical energy that is consumed but not used to produce new biomass in the process of energy transfer between trophic levels in an ecosystem?
A) It is undigested and winds up in the feces and is not passed on to higher trophic levels.
B) It is used by organisms to maintain their life processes through the reactions of cellular respiration.
C) Heat produced by cellular respiration is used by heterotrophs for thermoregulation.
D) It is eliminated as feces or is dissipated into space as heat as a result of cellular respiration consistent with the second law of thermodynamics.

Answer 1

D) It is eliminated as feces or is dissipated into space as heat as a result of cellular respiration
consistent with the second law of thermodynamics.

Question 2

Consider the food chain of grass-grasshopper-mouse-snake-hawk. About how much of the chemical energy fixed by photosynthesis of the grass (100 percent) is available to the hawk?
A) 0.01%
B) 0.1%
C) 1%
D) 10%

Answer 2

A) 0.01%

Question 3

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps
involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be accurate?
A) Polar bears can provide more food for humans than seals can.
B) The total biomass of the fish is lower than that of the seals.
C) Seal populations are larger than fish populations.
D) Fish can potentially provide more food for humans than seal meat.

Answer 3

D) Fish can potentially provide more food for humans than seal meat

Question 4

A porcupine eats 3,000 J of plant material. Of this, 2,100 J is indigestible and is eliminated as feces, 800 J are used in cellular respiration, and 100 J are used for growth and reproduction. What is the approximate production efficiency of this animal?
A) 0.03%
B) 3%
C) 11%
D) 33%

Answer 4

C) 11%

Question 5

Which of the following locations are major reservoirs for carbon in the carbon cycle?
A) the ocean, atmosphere, and fossilized and live plant and animal biomass
B) the atmosphere
C) fossilized plant and animal remains (coal, oil, and natural gas)
D) sediments and sedimentary rocks

Answer 5

A) the ocean, atmosphere, and fossilized and live plant and animal biomass

Question 6

Which of the following statements is correct about biogeochemical cycling?
A) Phosphorus is the limiting nutrient that most widely affects biomass production.
B) The phosphorus cycle involves the weathering of rocks.
C) The carbon cycle has maintained a constant atmospheric concentration of carbon dioxide for the past million years.
D) The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic components of the ecosystem

Answer 6

B) The phosphorus cycle involves the weathering of rocks

Question 7

Nitrifying bacteria participate in the nitrogen cycle mainly by ________.
A) converting nitrogen gas to ammonia
B) releasing ammonium from organic compounds, thus returning it to the soil
C) converting ammonium to nitrate, which plants absorb
D) incorporating nitrogen into amino acids and organic compounds

Answer 7

C) converting ammonium to nitrate

Question 8

The Hubbard Brook watershed deforestation experiment revealed that ________.
I) deforestation increased water runoff
II) nitrate concentration in waters draining the deforested area became dangerously high
III) calcium levels remained high in the soil of deforested areas
A) only I
B) only II
C) only III
D) only I and II

Answer 8

D) only I and II

Question 9

Why do logged tropical rain forest soils typically have nutrient-poor soils?
A) Tropical bedrock contains little phosphorous.
B) Logging results in soil temperatures that are lethal to nitrogen-fixing bacteria.
C) Most of the nutrients in the ecosystem are removed in the harvested timber.
D) The cation exchange capacity of the soil is reversed as a result of logging.

Answer 9

C) Most of the nutrients in the ecosystem are removed in the harvested timber

Question 10

How can biodiversity affect the way we decontaminate industrial sites?
I) Bacteria have been found to be able to detoxify certain chemicals; perhaps there are more.
II) Trees produce sawdust, which can be used to soak up chemicals.
III) Species evolving in contaminated areas could adapt and detoxify the area.
A) only I
B) only II
C) only III
D) only II and III

Answer 10

A) only I

Question 11

The first step in ecosystem restoration is to ________.
A) restore the physical structure
B) restore native species that have been extirpated due to disturbance
C) remove competitive invasive species
D) remove toxic pollutants

Answer 11

A) restore the physical structure

Question 12

The goal of restoration ecology is to ________.
A) replace a ruined ecosystem with a more suitable ecosystem for that area
B) return degraded ecosystems to a more natural state
C) manage competition among species in human-altered ecosystems
D) prevent further degradation by protecting an area with park status

Answer 12

B) return degraded ecosystems to a more natural state

Question 13

The discipline that applies ecological principles to returning degraded ecosystems to a more natural state is known as ________.
A) landscape ecology
B) conservation ecology
C) restoration ecology
D) resource conservation

Answer 13

C) restoration ecology

Question 14

Which of the following would be considered an example of bioremediation?
A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability
B) using a bulldozer to regrade a strip mine
C) dredging a river bottom to remove contaminated sediments
D) adding fertilizer to soil poor in nutrients to increase plant growth

Answer 14

A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability

Question 15

Acid precipitation lowered the pH of soil in a terrestrial ecosystem that supported a diverse community of plants and animals. The decrease in pH eliminated all nitrogen-fixing bacteria populations in the area. Which prediction most accurately reflects the impact this will have on
the community?
A) Since phosphorus can replace nitrogen as an essential nutrient, the impact will be minimal.
B) Plants can obtain the nitrogen necessary for growth from the atmosphere, but bacterial communities will be negatively impacted.
C) Primary producers will suffer from nitrogen deficiency and the entire community will experience a decrease in carrying capacity.
D) The decrease in pH actually increases the availability of soil nutrients, so other nutrients that were less available cause an increase in primary production and an increase in biomass at other
trophic levels.

Answer 15

C) Primary producers will suffer from nitrogen deficiency and the entire community will experience a decrease in carrying capacity

Question 16

Darwin and Wallace’s theory of evolution by natural selection was revolutionary because it ________.
A) was the first theory to refute the ideas of special creation
B) proved that individuals acclimated to their environment over time
C) dismissed the idea that species are constant and emphasized the importance of variation and change in populations
D) was the first time a biologist had proposed that species changed through time

Answer 16

C) dismissed the idea that species are constant and emphasized importance of variation and change in populations

Question 17

The Linnaeus classification system grouped organisms by ________.
A) linear hierarchy of the scala naturae
B) increasingly more general categories
C) increasingly more complex categories
D) environmental location

Answer 17

B) increasingly more general categories

Question 18

Fossils found in strata reveal that ________.
A) older strata carry fossils that differ greatly from living organisms
B) geologic changes occur quickly on Earth
C) unused body parts decrease in size
D) innate drive to complexity of life

Answer 18

A) older strata carry fossils that differ greatly from living organisms

Question 19

Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is ________.
A) a few thousand years old, and populations are unchanging
B) a few thousand years old, and populations gradually change
C) millions of years old, and populations rapidly change
D) millions of years old, and populations are unchanging

Answer 19

A) a few thousand years old, and populations are unchanging

Question 20

Which of the following statements best explains why modification or change in an organ or tissue during the lifetime of an individual is not inherited?
A) Characteristics acquired during an organism’s life are generally not passed on through genes.
B) Spontaneous mutations can result in the appearance of new traits.
C) Only favorable adaptations have survival value.
D) Disuse of an organ may lead to its eventual disappearance.

Answer 20

A) Characteristics acquired during an organism’s life are generally not passed on through genes

Question 21

When Cuvier considered the fossils found in the vicinity of Paris, he concluded that the extinction of species ________.
A) does not occur, but evolution does occur
B) and the evolution of species both occur
C) and the evolution of species do not occur
D) occurs, but that there is no evolution

Answer 21

D) occurs, but that there is no evolution

Question 22

For which one of the following observations were both Lamarck’s hypothesis and Darwin’s hypothesis in complete agreement?
A) Use and disuse of organs determines their size in progeny.
B) Gradual evolutionary change explains why organisms are well-suited to their environments.
C) Acquired characteristics are inherited.
D) More complex species are descended from less complex species.

Answer 22

B) Gradual evolutionary change explains why organisms are well-suited to their environments

Question 23

If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?
A) one stratum
B) two strata
C) three strata
D) four strata

Answer 23

B) two strata

Question 25

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by ________.
A) natural selection, because these traits evolved in the population over time
B) natural selection, because these traits were not consciously selected by humans
C) artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content
D) artificial selection, because these animals differ from their close relatives and common ancestor

Answer 25

C) artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content

Question 26

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct?
A) In this wild mustard, there is enough heritable variation to permit these different varieties.
B) Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics.
C) Natural selection is rare in wild populations of wild mustard.
D) In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.

Answer 26

A) In this wild mustard, there is heritable variation to permit these different varieties

Question 27

What are adaptations?
A) geologic changes over time
B) rocks containing fossils
C) inherited characteristics of organisms that enhance their survival
D) descent with modification from a common ancestor

Answer 27

C) inherited characteristics of organisms that enhance their survival

Question 28

Which of these conditions are always true of populations evolving due to natural selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
A) Condition 1 only
B) Condition 2 only
C) Conditions 1 and 2
D) Conditions 2 and 3

Answer 28

C) Conditions 1 and 2

Question 29

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these statements explains why the pigweed reappeared?
A) The herbicide company lost its triazine formula and started selling poor-quality triazine.
B) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species.
C) Triazine-resistant pigweed has less-efficient photosynthesis metabolism.
D) Triazine-resistant weeds were more likely to survive and reproduce.

Answer 29

D) Triazine-resistant weeds were more likely to survive and reproduce

Question 30

Which one of the following statements best defines artificial selection?
A) Process that occurs when individuals inherit traits that enable them to survive and reproduce
B) Process where humans decide which plants and/or animals will not breed
C) Process of human directed breeding aimed to produce selective traits in selected species
D) Process that favors beneficial mutations

Answer 30

C) Process of human directed breeding aimed to produce selective traits in selected species

Question 31

After the drought of 1977, researchers hypothesized that on the Galápagos Island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island?
A) evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks
B) evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks
C) increased variation in beak size and shape over time
D) no change in beak size and shape over time

Answer 31

C) increased variation in beak size and shape over time

Question 32

The following question is based on information from Frank M. Frey, “Opposing Natural Selection from Herbivores and Pathogens May Maintain Floral-Color Variation in Claytonia virginica (Portulacaceae),” Evolution 58(11), 2004: 2426-37.

Claytonia virginica is a woodland spring herb with flowers that vary from white, to pale pink, to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink to white flowers, so that Claytonia with pink flowers have greater relative fruit set than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time?
A) The percentage of pink flowers should increase over time.
B) The percentage of white flowers should increase over time.
C) The distribution of flower colors should not change.
D) The distribution of flower colors should randomly fluctuate over time.

Answer 32

A) The percentage of pink flowers should increase over time

Question 33

Which statement illustrates the connection between natural selection and overreproduction of a population?
A) Populations vary in their inherited traits.
B) Species produce more offspring than can survive in the environment.
C) Individuals with inherited traits that promote survival tend to have more surviving offspring.
D) Individuals with traits that do not enhance survival cannot reproduce.

Answer 33

C) Individuals inherited traits that promote survival tend to have more surviving offspring

Question 34

Darwin used the phrase “descent with modification” to explain ________.
A) unity of life
B) descent of all organisms from a single, ancient ancestor
C) that habitat differences stimulate change in organisms
D) evolution of the unity and diversity of life

Answer 34

D) evolution of the unity and diversity of life

Question 35

Which of the following statements describe evolution?
A) Individuals evolve in response to their environment.
B) The match between organism and their environment decreases.
C) Natural selection chooses the most popular trait.
D) Quick changes occur in an individual’s phenotype.

Answer 35

A) Individuals evolve in response to their environment

Question 36

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.
A) 2 → 4 → 1 → 3
B) 4 → 2 → 1 → 3
C) 4 → 2 → 3 → 1
D) 2 → 4 → 3 → 1

Answer 36

A) 2 → 4 → 1 → 3

Question 37

Which of the following factors could cause a surge in population size?
A) a decrease in available food
B) an increase in the number of predators
C) better eyesight evolves in the population
D) decreased camouflage evolves in the population

Answer 37

C) better eyesight evolves in the population

Question 38

Which of the following statements describe the effect of evolution on a population?
A) increasingly better match between a population and its environment
B) increased genetic variation among individuals in a population
C) increased variation among individuals in a population
D) increased sexual reproduction in a population

Answer 38

A) increasingly better match between a population and its environment

Question 39

Which of Darwin’s ideas had the strongest connection to his reading of Malthus’s essay on human population growth?
A) descent with modification
B) variation among individuals in a population
C) struggle for existence
D) that the ancestors of the Galápagos finches had come from the South American mainland

Answer 39

C) struggle for existence

Question 40

If Darwin had been aware of genes and their typical mode of transmission to subsequent
generations, with which statement would he most likely have been in agreement?
A) If natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones.
B) If an organism’s somatic cell genes change during its lifetime, making it more fit, then it will
be able to pass these genes on to its offspring.
C) If an organism acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will result.
D) A single mutation in a single gene in a single gamete, if inherited by future generations, will produce a new species.

Answer 40

A) If natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones

Question 41

Which one of the following observations did Darwin first make during his discovery of evolution?
A) The ability of individuals to survive and reproduce is not equal.
B) There is variation in inherited traits.
C) Individuals who reproduce more leave more offspring.
D) The unequal ability to reproduce leads to the accumulation of favorable traits in a population.

Answer 41

B) There is a variation in inherited traits

Question 42

Currently, two extant elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?
A) Species X and Y are not related to species Z.
B) Species X and Y share a greater number of homologies with each other than either does with species Z.
C) Species X and Y share a common ancestor that is alive today.
D) Species X and Y are the result of artificial selection.

Answer 42

B) Species X and Y share a greater number of homologies with each other than either does with species Z

Question 43

In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is least likely to result in the algae-eater population in future generations?
A) selection for drab coloration of the algae-eaters
B) selection for nocturnal algae-eaters (active only at night)
C) selection for larger female algae-eaters, bearing broods composed of more, and larger, young
D) selection for algae-eaters that become sexually mature at smaller overall body sizes

Answer 43

C) selection for lager female algae-eaters, bearing broods composed of more, and larger, young

Question 44

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should ________.
A) test whether other traits in these males are also adaptive
B) look for evidence of hair in ancestors of tamarins
C) determine if hair length is heritable
D) test whether males with shaved heads are still able to mate

Answer 44

C) determine if hair length is heritable

Question 45

Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that ________.
A) fossils found in a given area look like the modern species in that same area
B) the environment where it lived was very warm
C) mammals evolved from a reptilian ancestor
D) Antarctica and South Africa separated after Thrinaxodon went extinct

Answer 45

C) mammals evolved from a reptilian ancestor

Question 46

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________.
A) convergent evolution
B) a homologous structure
C) natural selection
D) a vestigial trait

Answer 46

D) a vestigial trait

Question 47

Scientific theories ________.
A) are nearly the same things as hypotheses
B) are supported by, and make sense of, many observations
C) cannot be tested because the described events occurred only once
D) are predictions of future events

Answer 47

B) are supported by, and make sense of, many observations

Question 48

DDT was once considered a “silver bullet” that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests?
A) All habitats should have received applications of DDT at about the same time.
B) The frequency of DDT application should have been higher.
C) None of the insect pests would have genetic variations that resulted in DDT resistance.
D) DDT application should have been continual.

Answer 48

C) None of the insect pests would have genetic variations that resulted in DDT resistance

Question 49

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics?
A) These genes would be maintained in case the antibiotics appear.
B) These bacteria would be outcompeted and replaced by bacteria that have lost these genes.
C) These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present.
D) The number of genes conveying antibiotic resistance would increase in these bacteria.

Answer 49

B) These bacteria would be outcompeted and replaced by bacteria that have lost these genes

Question 50

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?
A) bones in the hind limb of a kangaroo
B) chitinous struts in the wing of a butterfly
C) bony rays in the tail fin of a flying fish
D) bones in the flipper of a whale

Answer 50

D) bones in the flipper of a whale

Question 51

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ________.
A) homology
B) convergent evolution
C) the evolution of common structure as a result of common function
D) the evolution of similar appearance as a result of common function

Answer 51

A) homology

Question 52

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
A) Natural selection cannot account for losses, but accounts only for new structures and functions.
B) Natural selection accounts for these losses by the principle of use and disuse.
C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
D) The ancestors of these organisms experienced harmful mutations that forced them to lose these structures.

Answer 52

C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits

Question 53

Which of the following evidence most strongly supports the common origin of all life on Earth? All organisms ________.
A) require energy
B) use essentially the same genetic code
C) reproduce
D) show heritable variation

Answer 53

B) use essentially the same genetic code

Question 54

Members of two different species possess a similar-looking structure that they use in a
similar way to perform about the same function. Which of the following would suggest that the
relationship more likely represents homology instead of convergent evolution?
A) The two species live at great distance from each other.
B) The two species share many proteins.
C) The structures in adult members of both species are similar in size.
D) Both species are well adapted to their particular environments.

Answer 54

B) The two species share many proteins

Question 55

What must be true of any organ described as vestigial?
A) It must be analogous to some feature in an ancestor.
B) It must be homologous to some feature in an ancestor.
C) It must be both homologous and analogous to some feature in an ancestor.
D) It need be neither homologous nor analogous to some feature in an ancestor.

Answer 55

B) It must be homologous to some feature in an ancestor

Question 56

Pseudogenes are ________.
A) composed of RNA, rather than DNA
B) the same things as introns
C) unrelated genes that code for the same gene product
D) nonfunctional vestigial genes

Answer 56

D) nonfunctional vestigial genes

Question 57

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ________.
A) island forms are descended from mainland forms
B) common environments are inhabited by the same organisms
C) island forms and mainland forms have identical gene pools
D) the island forms and mainland forms are converging

Answer 57

A) island forms are descended from mainland forms

Question 58

Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years?
A) an isolated ocean island in the tropics
B) an extensive mountain range
C) a grassland in the center of a large continent, with extreme climatic conditions
D) a shallow estuary on a warm-water coast

Answer 58

A) an isolated ocean island in the tropics

Question 59

The greatest number of endemic species is expected in environments that are ________.
A) easily reached and ecologically diverse
B) isolated and show little ecological diversity
C) isolated and ecologically diverse
D) easily reached and show little ecological diversity

Answer 59

B) isolated and show little ecological diversity

Question 60

About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus
Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?
A) They should be limited to the six islands that most recently emerged from the sea.
B) Their genomes should be more similar to each other than are the genomes of the five tree
finch species.
C) They should share fewer anatomical homologies with each other than they share with the tree finches.
D) The chances of hybridization between two ground finch species should be less than the
chances of hybridization between two tree finch species.

Answer 60

B) Their genomes should be more similar to each other than they share with the tree finches

Question 61

The legless condition that is observed in several groups of extant reptiles is the result of ________.
A) their common ancestor having been legless
B) a shared adaptation to an arboreal (living in trees) lifestyle
C) several instances of the legless condition arising independently of each other
D) individual lizards adapting to a fossorial (living in burrows) lifestyle during their lifetimes

Answer 61

C) several instances of the legless condition arising independently of each other

Question 62

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of ________.
A) how widely the organisms assigned to each are distributed throughout the environment
B) their inclusiveness
C) the relative genome sizes of the organisms assigned to each
D) morphological characters that are applicable to all organisms

Answer 62

B) their inclusiveness

Question 63

If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
A) A and D
B) B and D
C) B and C
D) D and E

Answer 63

D) D and E

Question 64

Carolus Linnaeus believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with ________.
A) a hierarchical classification scheme
B) taxonomy
C) phylogenies
D) nested, increasingly inclusive categories of organisms

Answer 64

C) phylogenies

Question 65

The best classification system is that which most closely ________.
A) unites organisms that possess similar morphologies
B) conforms to traditional, Linnaean taxonomic practices
C) reflects evolutionary history
D) reflects the basic separation of prokaryotes from eukaryotes

Answer 65

C) reflects evolutionary history

Question 66

Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of ________.
A) convergent evolution
B) similarity due to shared ancestry
C) homology
D) parsimony

Answer 66

A) convergent evolution

Question 67

The term convergent evolution is most applicable to which of the following features?
A) the legless condition found in various lineages of extant lizards
B) the five-digit condition of human hands and bat wings
C) the fur that covers Australian moles and North American moles
D) the bones of bat forelimbs and the bones of bird forelimbs

Answer 67

A) the legless condition found in various lineages of extant lizards

Question 68

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be ________.
A) homology
B) convergent evolution
C) common ancestry
D) retro-evolution by humans

Answer 68

B) convergent evolution

Question 69

Which of the following pairs are the best examples of homologous structures?
A) eyelessness in the Australian mole and eyelessness in the North American mole
B) owl wing and hornet wing
C) bat wing and bird wing
D) bones in the bat wing and bones in the human forelimb

Answer 69

D) bones in the bat wing and bones in the human forelimb

Question 70

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to ________.
A) the inheritance of acquired characteristics
B) sexual selection
C) possession of analogous (convergent) traits
D) possession of shared primitive characters

Answer 70

C) possession of analogous (convergent) traits

Question 71

The importance of computers and of computer software to modern systematics is most closely linked to advances in ________.
A) light microscopy
B) radiometric dating
C) fossil discovery techniques
D) molecular genetics

Answer 71

D) molecular genetics

Question 72

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ________.
A) structural homologies
B) vestiges
C) structural analogies
D) the result of shared ancestry

Answer 72

C) structural analogies

Question 73

Imagine that a phylogeny was developed for a group of mammals based on bone structure. Which of the following statements would be a reasonable prediction about a phylogeny for the same group of species based on similarities and differences in the structure of a particular enzyme?
A) The same phylogeny would be unlikely.
B) The same phylogeny would be predicted.
C) No prediction could be made.
D) The amino acid sequence would be identical in all species.

Answer 73

A) The same phylogeny would be unlikely

Question 74

Which of the following would be most useful in creating a phylogenetic tree of a taxon?
A) morphological data from fossil and living species
B) a knowledge of color patterns in fossil and living species
C) a knowledge of mutation rates in modern species
D) morphological data from fossil species

Answer 74

D) morphological data from fossil species

Question 75

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?
A) to serve as an outgroup
B) to see if the lily is a cryptic orchid species
C) to see if the lily and the orchids show all the same shared derived characters
D) to demonstrate likely homoplasies

Answer 75

A) to serve as an outgroup

Question 76

Which of the following statements best describes the rationale for applying the principle of maximum parsimony in constructing phylogenetic trees?
A) Parsimony allows the researcher to “root” the tree.
B) Similarity due to common ancestry should be more common than similarity due to convergent evolution.
C) The molecular clock validates the principle of parsimony.
D) The outgroup roots the tree, allowing the principle of parsimony to be applied

Answer 76

B) Similarity due to common ancestry should be more common than similarity due to convergent evolution

Question 77

Which of the following statements is accurate with regard to a phylogeny, as represented by a phylogenetic tree?
A) Descendant groups (branches) from the same node likely share many derived characters.
B) A monophyletic group can be properly based on convergent features.
C) The ancestral group often has all the derived characters of the descendant species.
D) Shared ancestral characters are excellent traits to use in developing a phylogeny.

Answer 77

A) Descendant groups (branches) from the same node likely share many derived characters

Question 78

Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history?
A) polyphyletic taxa
B) paraphyletic taxa
C) monophyletic taxa
D) polyphyletic taxa and paraphyletic taxa

Answer 78

D) polyphyletic taxa and paraphyletic taxa

Question 79

Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in ________.
A) morphology
B) the pattern of embryological development
C) biochemical pathways
D) mutations to homologous genes

Answer 79

D) mutations to homologous genes

Question 80

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then hair is a shared ________.
A) derived character of mammals, even if cynodonts continue to be classified as reptiles
B) derived character of all vertebrates and not of the mammal clade
C) ancestral character of the all vertebrates, but only if cynodonts are reclassified as mammals
D) derived character of mammals, but only if cynodonts are reclassified as mammals

Answer 80

D) derived character of mammals, but only if cynodonts are reclassified as mammals

Question 81

In a comparison of birds and mammals, having four limbs is ________.
A) a shared ancestral character
B) a shared derived character
C) a character useful for distinguishing birds from mammals
D) an example of analogy rather than homology

Answer 81

A) a shared ancestral character

Question 82

To apply the principle of maximum parsimony to construction of a phylogenetic tree, ________.
A) choose the tree that assumes all evolutionary changes are equally probable
B) choose the tree in which the branch points are based on as many shared derived characters as possible
C) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology
D) choose the tree with the fewest branch points

Answer 82

C) choose the tree that represents the fewest evolutionary changes, either in DNAA sequences or morphology

Question 83

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?
A) lion
B) domestic cat
C) wolf
D) leopard

Answer 83

C) wolf

Question 84

Concerning growth in genome size over evolutionary time, which of these is least associated with the others?
A) orthologous genes
B) gene duplications
C) paralogous genes
D) gene families

Answer 84

A) orthologous genes

Question 85

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ________.
A) plasmids
B) mitochondrial genomes
C) homologous genes that are poorly conserved
D) homologous genes that are highly conserved

Answer 85

D) homologous genes that are highly conserved

Question 86

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of ________.
A) archaeans and bacteria
B) fungi and animals
C) chimpanzees and humans
D) sharks and dolphins

Answer 86

C) chimpanzees and humans

Question 87

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about 10 thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?
A) conserved regions of nuclear DNA
B) mitochondrial DNA
C) amino acids in proteins
D) ribosomal RNA

Answer 87

B) mitochondrial DNA

Question 88

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves ________.
A) have very similar morphologies
B) belong to the same order
C) are both members of the order Carnivora
D) share a very recent common ancestor

Answer 88

D) share a very recent common ancestor

Question 89

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.
A) having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild
B) paralogous genes can occur only in diploid species, thus they are absent from most prokaryotes
C) polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild
D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product

Answer 89

D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product

Question 90

The most important feature that permits a gene to act as a molecular clock is ________.
A) a large number of base pairs
B) being acted upon by natural selection
C) a reliable average rate of mutation
D) a recent origin by a gene-duplication event

Answer 90

C) a reliable average rate of mutation

Question 91

Molecular clocks are more reliable when ________.
A) the surrounding pH is close to 7.0
B) most mutations of highly conserved DNA sequences should have no functional effect
C) the DNA codes for amino acid sequences whose side groups (or R groups) have a neutral pH
D) a significant proportion of mutations are not acted upon by natural selection

Answer 91

D) a significant proportion of mutations are not acted upon by natural selection

Question 92

Which of the following would, if it had acted upon a gene, prevent this gene from acting as a reliable molecular clock?
A) neutral mutations
B) genetic drift
C) mutations within introns
D) natural selection

Answer 92

D) natural selection

Question 93

Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable?
A) Plantae
B) Fungi
C) Animalia
D) Protista

Answer 93

D) Protista

Question 94

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?
A) Plantae
B) Fungi
C) Animalia
D) Protista

Answer 94

A) Plantae

Question 95

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?
A) Among themselves, they should share relatively few ancestral traits, especially those that enabled ancestral forms to adapt to extreme conditions.
B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.
C) They should contain genes that originated in eukaryotes that are the hosts for numerous species of bacteria.
D) They should currently be undergoing a high level of horizontal gene transfer with non-extremophilic archaeans.

Answer 95

B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.

Question 96

Use the following information to answer the question.
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated “chromatophores.” The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.A crucial photosynthetic gene of the cyanobacterium that gave rise to the chromatophore is called psaE. This gene is present in the nuclear genome of the cercozoan, but is not in the genome of the chromatophore. This is evidence of ________.
A) reciprocal mutations in the chromatophore and nuclear genomes
B) horizontal gene transfer from bacterium to eukaryotes
C) genetic recombination involving a protist and an archaean
D) transduction by a phage that infects both prokaryotes and eukaryotes

Answer 96

B) horizontal gene transfer from bacterium to eukaryotes

Question 97

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?
A) mtDNA
B) rRNA genes
C) morphological
D) ecological

Answer 97

B) rRNA genes

Question 98

Which of the following statements is accurate, at least according to our present knowledge?
A) Eukaryotes acquired nuclear genes only in the distant past; these genes can allow survival in anaerobic environments.
B) Genes from prokaryotes have been acquired by some eukaryotes; these genes can allow survival in extreme environments.
C) Prokaryotes acquired genes from eukaryotes many times; these genes can allow survival in extreme environments.
D) Prokaryotes acquired genes from fungi; these genes can allow the digestion of cellulose.

Answer 98

B) Genes from prokaryotes have been acquired by some eukaryotes; these genes can allow survival in extreme environments

Question 99

If additional DNA sequence evidence shows that yeast genes for synthesizing proteins are more similar to protein-synthesizing genes in bacteria than those in archaea, a modern
systematist would ________.
A) redraw the phylogeny to show eukaryotes sharing a more recent common ancestor with bacteria than archaea
B) redraw the phylogeny to show more recent common ancestry between archaea and yeast than between eukaryotes and archaea
C) retain the phylogeny that shows a more recent common ancestor between eukaryotes and archaea
D) retain the phylogeny that shows a more recent common ancestor between bacteria and archaea

Answer 99

A) redraw the phylogeny to show eukaryotes sharing a more recent common ancestor with bacteria than archaea

Question 100

Which of the following statements about horizontal gene transfer is accurate?
A) Horizontal gene transfer was quite common in the early stages of evolution of life on Earth.
B) Horizontal gene transfer among organisms does not occur today.
C) Horizontal gene transfer moves only genes that play a role in metabolism.
D) Horizontal gene transfer occurs only among closely related organisms.

Answer 100

A) Horizontal gene transfer was quite common in the early stages of evolution of life on Earth

Question 101

The kingdom Monera was dismantled because of which of the following reasons?
A) Some Monera contained nuclei in their cells.
B) The Monera, as originally constituted, contained both plants and animals.
C) The Monera, as originally constituted, was monophyletic.
D) Some, but not all, of the organisms in Monera contained DNA sequences that were similar to those of eukaryotes

Answer 101

D) Some, but not all, of the organisms in Monera contained DNA sequences that were similar to those of eukaryotes

Question 102

If you pound a nail into a tree 1 meter off the ground and come back to find it in 25 years, it will be _____
A. 1 meter off the ground and more deeply embedded in the tree.
B. more than 1 meter off the ground and more deeply embedded in the tree.
C. more than 1 meter off the ground and the same depth in the tree.
D. 1 meter off the ground and the same depth in the tree.
E. less than 1 meter off the ground but at the same depth in the tree.

Answer 102

A

Question 103

Suppose S. Duterte completely removed the bark from around one meter above the base of a mango tree but was stopped by her father. The leaves retained their normal appearance for several weeks, but the tree eventually died. The tissue(s) that S. Duterte left functional was (were) the _____.
A. phloem
B. cortex
C. companion and sieve-tube members
D. xylem
E. cork cambium

Answer 103

D.

Question 104

The vascular system of a three-year-old eudicot stem consists of
A. 3 rings of xylem and 3 of phloem.
B. 2 rings of xylem and 1 of phloem.
C. 2 rings of xylem and 2 of phloem.
D. 3 rings of xylem and 2 of phloem.
E. 3 rings of xylem and 1 of phloem

Answer 104

E

Question 105

For this pair of items, choose the option that best describes their relationship.
(A) the number of vessel elements in a eudicot root cap
(B) the number of vessel elements in a eudicot stem

A. Item (A) is less than item (B).
B. there is no relationship between the pair of items
C. Item (A) is exactly or very approximately equal to item (B).
D. Item (A) may stand in more than one relations to item (B).
E. Item (A) is greater than item (B).

Answer 105

A

Question 106

_______ is the white blood cell that gives rise to macrophages while _______ is the mature white blood cell that produces antibodies
A. Lymphocyte; mast cell
B. Lymphocyte; plasma cell
C. Monocyte; mast cell
D. Monocyte; plasma cell
E. Eosinophil; basophil

Answer 106

D

Question 107

Given the following:

1. Position of nucleus/nuclei
2. Number/s of nucleus/nuclei
3. Type of control
4. Presence of striations
   Which criterion/criteria is/are used to distinguish cardiac from skeletal muscles?
   A. 1, 2, 3
   B. 1, 2, 3, 4
   C. 1 & 3 only
   D. 2 & 3 only
   E. 1 & 4 only

Answer 107

A.

Question 108

Given the following:

I - the number of neuroglial cells in the brain tissue

II - the number of nerve cells in the brain tissue

A. II is greater than I
B. I is not related to II
C. I is equal to II
D. I is greater than II
E. I is in several relationships to II

Answer 108

D

Question 109

How can squamous epithelium, which have a high surface area to volume ratio both facilitate diffusion and prevent damage from abrasion?
A. Single layer of squamous epithelia facilitate gas, nutrient or waste exchange whereas stratified layers provide protection and are replaceable following damage
B. Single layer of squamous epithelia facilitate only exchange of gases by diffusion whereas stratified layers provide protection and are replaceable following damage
C. Single layer of squamous epithelia facilitate gas, nutrient or waste exchange whereas stratified layers provide protection and are not replaceable following damage
D. Stratified layer of squamous epithelia facilitate gas, nutrient or waste exchange whereas single layer provide protection and are replaceable following damage

Answer 109

A

Question 110

Stomata are usually found in higher numbers on the abaxial surface of a leaf. Demonstrate why this is the case by explaining the advantage of such an arrangement.
A. The abaxial surface receives more sunlight and water evaporates faster by transpiration
B. The adaxial surface receives more sunlight and water evaporates faster by transpiration
C. Presence of stomata on the abaxial surface ensures that no or very little water is lost due to guttation
D. Herbivores are more likely to not eat leaves with stomata on the abaxial surface

Answer 110

B

Question 111

Which tissue makes up the husk of coconut?
A. collenchyma
B. meristems
C. parenchyma
D. sclerenchyma

Answer 111

D

Question 112

Which cells are no longer capable of carrying out the process of DNA transcription?
A. xylem parenchyma and tracheids
B. xylem parenchyma and vessels
C. xylem and sieve tube elements
D. companion cells and sieve tube elements

Answer 112

C

Question 113

Given:

I - the velocity of nerve impulse in naked axon

II - the velocity of nerve impulse in myelinated axon

A. I is greater than II
B. I is not related to II
C. II is greater than I
D. I is equal to II

Answer 113

C

Question 114

Columnar epithelial cells, which are typically found in a single layer arrangement, are found along the digestive tract. What is the role of the columnar epithelial cells in digestion
A. Columnar epithelial cells secrete enzymes like salivary enzymes like ptyalin which aid in digestion by the breakdown of carbohydrates in the body
B. Columnar epithelial cells secrete mucus for lubrication as well as anti microbial agents in the digestive tract
C. Columnar epithelial cells help in the propulsion of food by peristalsis in the digestive tract of the body
D. Columnar epithelial cells absorb material from the lumen of the digestive tract to prepare the material for entry into the body

Answer 114

D

Question 115

In vertebrates cartilage is found in fetal bone, ears, and intervertebral discs, whereas bone is found in the skeleton. What are the similarities between cartilage and bone?
A. Both are types of connective tissues in the body that have originated from the endoderm
B. Both consists of bone marrow and have organic matrix material that provides strength and flexibility
C. Both are types of connective tissues in the body and cells of both are known as chondrocytes
D. Both are types of connective tissues in the body and have organic matrix material that provides strength and flexibility

Answer 115

D

Question 116

Given the following, classify the goblet cell.

1. unicellular gland
2. multicellular gland
3. mucus secreting
4. serous secreting
5. holocrine
6. merocrine
7. apocrine

A. 1, 3, 5
B. 1, 3, 6
C. 1, 4, 5
D. 2, 3, 6

Answer 116

B

Question 117

Which of the following statements about hormones that promote homeostasis is incorrect?
A. A stimulus causes an endocrine cell to secrete a particular hormone.
B. The hormone travels in the bloodstream to target cells.
C. Specific receptors bind with the hormone.
D. This response feeds back to promote the release of more hormone.
E. Signal transduction brings about a response in the target cell.

Answer 117

D

Question 118

Which of the following statements about the adrenal gland is correct?
A. At all times, the anterior portion secretes ACTH, while the posterior portion secretes oxytocin
B. At all times, the adrenal gland monitors calcium levels in the blood and regulates calcium by secreting the two antagonistic hormones, epinephrine and norepinephrine.
C. During stress, TSH stimulates the adrenal cortex and medulla to secrete acetylcholine.
D. During stress, the alpha cells of islets secrete insulin and simultaneously the beta cells of the islets secrete glucagon.
E. During stress, ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla.

Answer 118

E

Question 119

The same hormone has considerably different effects in different species. The hormone thyroxine in humans, for example stimulates metabolism, but in frogs it induces metamorphism from tadpole to adult frog. Why?
A. The structure of protein receptors in the target tissues differ.
B. The chemical composition of the hormone is actually slightly different.
C. The chemical structure of the hormone will result to signal transduction pathway at the target cell.
D. The origin of the hormone makes a difference in the effect the hormone has on target tissues.
E. Metamorphosis is caused by a change in body metabolism.

Answer 119

A

Question 120

Which of the following is not part of homeostasis promotion or maintenance?
A. Secretin promotes an increase in the pH of the duodenum.
B. Signal transduction brings about a response in the target cell.
C. A hormone is involved in a positive feedback loop.
D. A stimulus causes an endocrine cell to secrete a particular hormone, which decreases the stimulus.
E. A hormone acts in an antagonistic way with another hormone.

Answer 120

C

Question 121

Which of the following statements about hormones is correct?
A. Steroid hormones affect the synthesis of proteins to be exported from the cell, whereas peptide hormones affect the synthesis of proteins that remain in the cell.
B. Steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA.
C. Steroid and peptide hormones produce different effects but use the same biochemical mechanisms.
D. Steroid and peptide hormones produce the same effects but differ in the mechanisms that produce the effects.
E. Steroid hormones affect the synthesis of proteins, whereas peptide hormones affect the activity of proteins already present in the cell.

Answer 121

E

Question 122

Congenital hypothyroidism is the severe deficiency of thyroid hormone in newborns. Since this hormone sends a negative feedback to the hypothalamus, what do you expect the hypothalamus and pituitary gland response to be? What will be the expected levels of thyrotropin-releasing hormone (TRH) and thyroid stimulating hormone (TSH)?
A. Increased TRH and increased TSH levels
B. Decreased TRH and increased TSH levels
C. Decreased TRH and decreased TSH levels
D. Increased TRH and decreased TSH levels
E. No effect on the TRH and TSH levels

Answer 122

A

Question 123

Action of parathormone in response to low calcium levels includes all of the following except
A. Stimulates conversion of vitamin D in the kidney
B. Increases calcium & phosphate reabsorption in the intestines
C. Increases calcium reabsorption
D. Increases bone resorption
E. Increases phosphate reabsorption

Answer 123

E

Question 124

Responses of body’s effectors to high temperature include
A. Contraction of arrector pili muscle
B. Vasoconstriction
C. Adrenal glands secrete adrenaline
D. Vasodilation
E. Goose bumps

Answer 124

D

Question 125

All of the following help regulate blood glucose level except
A. Glucagon stimulates the conversion of glycogen to glucose
B. Insulin promotes conversion of glucose to glycogen
C. Glucagon stimulates the conversion of pyruvic acid to glucose
D. Insulin promotes conversion of pyruvic acid to glucose
E. Insulin promotes conversion of glucose to pyruvic acid

Answer 125

D

Question 126

Diuretics like coffee, tea and alcoholic beverages result to increase urine output. This is attributed to
A. more water is reabsorbed from the urine
B. opening of aquaporin channels at the collecting ducts
C. decrease secretion of vasopressin
D. low blood water potential
E. increase secretion of ADH

Answer 126

C

Question 127

Which of the following statements about plant hormones is false?
A. Cytokinins promote cell division.
B. Gibberellins stimulate cell enlargement.
C. Abscisic acid generally promotes growth.
D. Ethylene contributes to the aging of plants.
E. The growth of plants in nature is probably regulated by a combination of growth-stimulating and growth-inhibiting hormones.

Answer 127

C

Question 128

Cells elongate in response to auxin. All of the following are part of the acid growth hypothesis except
A. The turgor pressure of the cell exceeds the restraining pressure of the loosened cell wall, and the cell takes up water and elongates.
B. Auxin stimulates proton pumps in cell membranes.
C. Lowered pH results in the breakage of cross-links between cellulose microfibrils.
D. The wall fabric becomes looser (more plastic).
E. Auxin-activated proton pumps stimulate cell division in meristems.

Answer 128

E

Question 129

You are part of a desert plant research team trying to discover crops that will be productive in arid climates. You discover a plant that produces a guard cell hormone under water-deficit conditions. Most likely the hormone is
A. salicylic acid.
B. 2, 4-D.
C. IAA.
D. ABA.
E. GA.

Answer 129

D

Question 130

Why do coleoptiles grow toward light?
A. Gibberellins are destroyed by light.
B. Auxin moves away from the light to the shady side.
C. Gibberellins move away from the light to the shady side.
D. Auxin synthesis is stimulated in the dark.
E. Auxin is destroyed by light.

Answer 130

B

Question 131

Cutting the sweet potato tops or shoot apices (talbos) result to bushy camote plant. This is attributed to _____________ due to the hormone ______________
A. lateral growth; gibberellin
B. lateral growth; cytokinin
C. apical dominance; auxin
D. lateral growth; auxin
E. apical dominance; gibberellin

Answer 131

C

Question 132

Annual plants like rice, corn, banana illustrate which of the following?
A. semelparous
B. emigration
C. dispersion
D. iteroparous
E. cohort

Answer 132

A

Question 133

A population is correctly defined as having which of the following characteristics?
I. inhabiting the same general area
II. individuals belonging to the same species
III. possessing a constant and uniform density and dispersion

A. I, II, III are all correct
B. II and III only
C. None of the choices is correct
D. I and II only
E. I and III only

Answer 133

D

Question 134

A populationʹs carrying capacity
A. may change as environmental conditions change.
B. increases as growth rate decreases.
C. generally remains constant over time.
D. can be accurately calculated using the logistic growth model.
E. increases as growth rate increases.

Answer 134

A

Question 135

Which of the following characterizes relatively r - selected populations?
A. intensive parenting
B. few offspring
C. slow maturation
D. a high intrinsic rate of increase
E. offspring with good chances of survival

Answer 135

D

Question 136

Consider several human populations of equal size and net reproductive rate, but different in age structure. The population that is likely to grow the most during the next 30 years is the one with the greatest fraction of people in which age range?
A. 30 to 40 years
B. 10 to 20 years
C. 40 to 50 years
D. 20 to 30 years
E. 50 to 60 years

Answer 136

B

Question 137

This project hopes to solve Metro Manila’s water requirements but will lead to environmental destruction and the displacement of indigenous peoples in more than 230 hectares of the Sierra Madre mountain range.
A. Kaliwa Dam Project
B. Angat Dam Expansion Project
C. Chico River Project
D. Kanan Dam Project
E. Angat-Ipo-La Mesa Dam system,

Answer 137

A

Question 138

Which of the following statements is consistent with the principle of competitive exclusion?
A. Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species.
B. Evolution tends to increase competition between related species.
C. Bird species generally do not compete for nesting sites.
D. The density of one competing species will have a positive impact on the population growth of the other competing species.
E. Two species with the same fundamental niche will exclude other competing species.

Answer 138

A

Question 139

Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees?
A. protocooperation
B. facilitation
C. commensalism
D. parasitism
E. mutualism

Answer 139

D

Question 140

Which of the following examples best describes an ecological community?
A. The interactions of all the plant and animal species inhabiting a 2 hectare forest.
B. The intraspecific competition of members of a goby population inhabiting a stream during a given year.
C. The material cycling and energy transformations between the biotic and abiotic components of a grassland.
D. The various species of Mytilus competing for resources in an intertidal zone.
E. The interactions of the various plant and animal species of park, excepting the decomposers.

Answer 140

A.

Question 141

Keystone predators can maintain species diversity in a community if they
A. reduce the number of disruptions in the community.
B. allow immigration of other predators.
C. competitively exclude other predators.
D. prey on the communityʹs dominant species.
E. prey only on the least abundant species in the community.

Answer 141

D

Question 142

What is the most important role of photosynthetic organisms in an ecosystem?
A. recycling energy from other tropic levels
B. absorbing solar radiation
C. producing organic detritus for decomposers
D. converting inorganic compounds into organic compounds
E. dissipating heat

Answer 142

D

Question 143

A secondary consumer, such as a snake, receives what percent of the energy fixed by primary producers in a typical field ecosystem?
A. 0.01%
B. 0.1%
C. 1%
D. 90%
E. 10%

Answer 143

C

Question 144

Which of the following is caused by excessive nutrient runoff into the Laguna de Bay?
A. turnover
B. greenhouse effect
C. biological magnification
D. eutrophication
E. depletion of atmospheric ozone

Answer 144

D

Question 145

This is National Geographic’s global initiative aimed at raising awareness about the crisis to reduce the amount of single-use plastic reaching the ocean.
A. The “Ocean Cleanup” project
B. The “Planet Soup” project
C. The “Planet or Plastic?” exhibition
D. The “Planet Plastic” exhibition
E. The “Planet Earth” project

Answer 145

C

Question 146

You have a friend who lost 7 kg (about 15 pounds) of fat on a ʺlow carbʺ diet. How did the fat leave her body?
A. It was released as CO2 and H2O.
B. It was converted to ATP, which weighs much less than fat.
C. It was converted to urine and eliminated from the body.
D. It was broken down to amino acids and eliminated from the body.
E. Chemical energy was converted to heat and then released.

Answer 146

A