Exam #1
Under which of the following conditions could evolution by natural selection not occur? A) no genetic variation in a population B) very long generation times C) very stable environment D) no predation
A
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) Natural selection is rare in wild populations of wild mustard. B) In this wild mustard, there is enough heritable variation to permit these different varieties. C) Heritable variation is low in wild mustard- otherwise this wild strain would have different characteristics. D) In wild mustard, most of the variation is due to difference in soil or other aspects of the environment.
B
Which of the following statements about energy is FALSE? A) It cannot be destroyed B) It is recycled in an ecosystem C) It represents the capacity to do work D) It can be stored in the chemical bonds of macromolecules
B
Which of the following is NOT true about a gene pool? A) It represents all copies of every allele in a population B) It represents all the gametes in a population C) It always comprised of two alleles or traits per gene or character D) All statements are true
C
p+q=
1
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCc?
2^3 = 8
A population is a group of individuals of the same species. According to the the theory of natural selection, what is likely to happen to a population when a change occurs in its environment? A) The individuals that have traits better suited to the changed environment would be more likely to survive and reproduce than those with less suitable traits. B) All of the individuals would try to develop new traits so that they could survive and reproduce in the changed environment. C) Some of the individuals would try to develop new traits so that they could survive and reproduce, and the other individuals would die. D) Because all individuals of the same species have the same traits, one individual would never have an advantage over another in its population. They would either all survive or all die.
A
According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that ________. A) speciation occurred rapidly in geologic time B) the species is now extinct C) speciation occurred in one generation D) the species will consequently have a relatively short existence, compared with other species
A
Darwin and Wallace's theory of evolution by natural selection was revolutionary because it _____. A) dismissed the idea that species are constant and emphasized the importance of variation and change in the populations B) was the first theory to refute the ideas of special creation C) proved that individuals acclimated to their environment over time D) was the first time a biologist had proposed that species changed through time
A
Individual members of a species could have differences in inherited characteristics that affect which of the following? A) Both their ability to find food and their ability to avoid predators B) Their ability to find food but not their ability to avoid predators C) Their ability to avoid predators but not their ability to find food D) Neither their ability to find food nor their ability to avoid predators
A
Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? A) a behavioral reproductive isolating mechanism B) a temporal reproductive isolating mechanism C) a postzygotic isolating mechanism D) a gametic reproductive isolating mechanism
A
Which of the following does not provide evidence for evolution? A) Heterozygous genotypes B) The fossil record C) Direct laboratory observation D) Island Biogeography
A
Which of the following is true about how changes can happen to the physical environment of earth? A) Changes can happen suddenly or gradually. B) Changes can happen suddenly but not gradually. C) Changes can happen gradually but not suddenly. D) Changes can happen neither gradually nor suddenly because the environment does not change.
A
Which of the following statements best distinguishes hypotheses from theories in science? A) Hypotheses are relatively narrow in scope; theories have broader explanatory power. B) Hypotheses are guesses, theories are correct answers. C) Theories are proved true; hypotheses are often contradicted by experimental results. D) Theories are hypotheses that have been proved.
A
Which two domains are most closely related?
Archaea and Eukarya
A hybrid zone is properly defined as A) an area where the ranges of two closely related species overlap, but do not interbreed B) an area where mating occurs between members of two closely related species, producing viable offspring. D) a zone where sterile hybrids form, kept separate by post zygotic barriers E) an area where members of two closely related species intermingle, but experience no gene flow.
B
A population of organisms will not evolve if _____. A) the population size is large B) all individual variation is due only to environmental factors C) the environment is changing at a relatively slow rate D) the population lives in a habitat without competing species present
B
During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? A) Only favorable adaptations have survival value. B) Characteristics acquired during an organism's life are generally not passed on through genes. C) Spontaneous mutations can result in the appearance of new traits. D) Disuse of an organ may lead to its eventual disappearance.
B
Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons EXCEPT that A) peas show easily observed variations in a number of characters, such as pea shape and flower color B) peas have an usually long generation time C) it is possible to control matings between different pea plants D) many of the observable characters that vary in pea plants are controlled by single genes
B
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? A) the evolution of common structure as a result of common function B) homology C) convergent evolution D) the evolution of similar appearance as a result of common function
B
The inability of organisms to evolve anything that could be an advantage reflects _____. A) the consequences of inbreeding B) the limits of historical constraints C) the inability to compromise D) the consequences of random mutations
B
Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate? A) reduced hybrid fertility B) reduced hybrid viability C) hybrid breakdown D) gametic isolation
B
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants? A) There is considerable genetic variation in garden peas. B) Traits are inherited in discrete units and are not eh results of "blending" C) Genes are composed of DNA D) Recessive genes occur more frequently in the F1 generation than do dominant ones
B
Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus _____. A) two alleles are present in equal proportions B) the allele's frequency should not change from one generation to the next C) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency D) individuals within the population are evolving
B
Which is an example of natural selection? A) Horses bred for strength B) A flower that is more attractive to pollinators have better reproductive success C) A late spring storm kills all the young plants in a given area D) Giraffes wanted to have longer necks and thus stretched their necks longer.
B
Which of the following is not an observation or inference on which natural selection is based? A) There is heritable variation among individuals B) Poorly adapted individuals never produce offspring C) Species produce more offspring than the environment can support D) Overtime favorable traits accumulate in the populations
B
Which of the following observations led to Darwin's idea of natural selection? A) Organisms only go extinct when catastrophes occur B) Members of a population vary in their heritable traits C) Body parts that are not used deteriorate over time D) All of the above
B
What are the three domains?
Bacteria, Archaea, Eukarya
A localized group of organisms that belong to the same species is called a A) ecosystem B) community C) population D) family
C
How does energy move through an ecosystem? A) Sunlight is the only source. B) It is recycled within the ecosystem, being constantly reused. C) It flows in through a system being transferred from one form to another. D) It flows through the system, with some lost in the process.
C
In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because ________. A) the population is doubling in number B) the population is diploid C) heterozygotes can come about in two ways D) heterozygotes have two alleles
C
Microevolution refers to the A) Change of allelic frequencies in bacteria over generations B) Change of allelic frequencies in a single species over generations C) Change of allelic frequencies in a population over generations D) Change of allelic frequencies in a community over generations
C
People who characterize evolution as "just a theory" show that they A) know the difference between a hypothesis and a theory B) understand how science accumulates information about the natural world C) think scientists use the term "theory" as a synonym for "hypothesis" D) understand how to develop scientific experiments
C
The first life arose on planet earth about A) 4.6 billion years ago B) 4.6 million years ago C) 3.5 billion years ago D) 3.5 million years ago
C
What is the correct order from small to large? A) molecules, cells, tissues, ecosystems, communities B) cells, organelles, organ system, community, ecosystems C) molecules, organism, population, communities, biosphere D) organelles, cells, population, biosphere, ecosystems
C
Which of the following does NOT demonstrate the unity among all organisms? A) Cells compose all living things B) Cells are the smallest unit of life C) All cells contain DNA in their nucleus D) All cells come from pre-existing cells
C
Which of the following does not precede the origin of life: A) Packaging of molecules into protocells B) Abiotic synthesis of small organic molecules C) Formation of a nucleus D) Joining of these small molecules into macromolecules
C
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 explanations best explains what happened? 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.
D
Cells are _____. A) only found in pairs, because single cells cannot exist independently B) limited in size to 200 and 500 micrometers in diameter C) characteristic of eukaryotic but not prokaryotic organisms D) characteristic of prokaryotic and eukaryotic organisms
D
For biologists studying a large flatworm population in the lab, which Hardy-Weinberg condition is most difficult to meet? A) no gene flow B) no selection C) no genetic drift D) no mutation
D
Which of the following is (are) true of natural selection? A) It requires genetic variation B) It results in descent with modification C) It involves differential reproductive success D) It requires genetic variation, results in descent with modification, and involves differential reproductive success
D
How do you get genetic variation in a population? A) Mutations B) Migrations C) Sexual recombination D) All of the above
D
How does a scientific theory differ from a scientific hypothesis? A) Theories are proposed to test scientific hypotheses. B) Hypotheses are usually an explanation for a more general phenomenon; theories typically address more specific issues. C) Confirmed theories become scientific laws, hypotheses become theories. D) Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues.
D
Prokaryotes are classified as belonging to two different domains. What are the domains? A) Bacteria and Protista B) Bacteria and Eukarya C) Archaea and Monera D) Bacteria and Archaea
D
Which of the following is REQUIRED for the process of natural selection to occur? A) Numerous species must have recently become extinct B) A food source must disappear C) There must be a sudden environmental change D) Traits must be inherited from one generation to the next
D
Some organisms, such as a chimpanzee and human have many similarities. Others, such as a chicken and an oak tree have fewer similarities. What is TRUE about the ancestors of these organisms? A) Chimpanzees and humans share a common ancestor with each other, but chickens and oak trees do not share a common ancestor with each other. B) Chimpanzees and humans share a common ancestor with each other, and chickens and oak trees share a common ancestor with each other, but chimpanzees and humans do not share a common ancestor with chickens and oak trees. C) Because chimpanzees, humans, chickens, and oak trees are separate species, none of them shares a common ancestor with any other. D) Chimpanzees, humans, chickens, and oak trees all share an ancient common ancestor.
D
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? A) By identifying the bones as being homologous B) By identifying the bones as being analogous C) By proposing that humans, bats, and dolphins share a common ancestor D) A and C only
D
What is TRUE about environmental conditions on earth? A) Environmental conditions on earth have always been the same, except for minor changes from year to year. B) Environmental conditions on earth changed in the past, but they are not changing now. C) Environmental conditions on earth stayed the same in the past, but they are changing now. D) Environmental conditions on earth changed in the past, and they are changing now.
D
Which of the following best demonstrates the unity among all organisms? A) molecule, cell, tissue, organelle, organism, population, community, ecosystem B) molecule, organelle, cell, tissue, organism, community, population, ecosystem C) molecule, organelle, cell, tissue, organism, population, ecosystem, community D) molecule, organelle, cell, tissue, organism, population, community, ecosystem
D
Which of the following correctly describes what happens when a population of bacteria becomes resistant to an antibiotic? A) During treatment with an antibiotic, each individual bacterium tries to become resistant to the antibiotic. Only some are able to willingly become resistant, and these individuals survive to pass this trait to their offspring. B) During treatment with an antibiotic, all of the bacteria gradually become more resistant to the antibiotic the more they are exposed to it. They all survive and pass this trait to their offspring. C) During treatment with an antibiotic, a population of bacteria usually dies. Sometimes by chance, all members of the population become resistant at once, survive, and pass their resistance to their offspring. D) During treatment with an antibiotic, only those individual bacteria that already have a trait that helps them survive the effects of the antibiotic will live. Their offspring in the next generation will also have this trait.
D
Which of the following is the most predictable outcome of increased gene flow between two populations? A) increased genetic difference between the two populations B) lower average fitness in both populations C) higher average fitness in both populations D) decreased genetic difference between the two populations
D
Which of the following is true about the extinction of species? A) Very few species have ever become extinct. Most continue to exist. B) There have been extinction events in which many species became extinct at about the same time. Aside from these, extinction is very rare. C) Up until recently, species have rarely became extinct. Humans have caused the majority of extinctions. D) Many species have become extinct throughout the history of life on earth.
D
Which of the following types of cells utilize DNA as their genetic material but do not have their DNA encased within a nuclear envelope? A) fungi B) animal C) plant D) prokaryote
D
Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? A) The traits blended together during fertilization B) No genes interacted to produce the parental phenotype C) Each allele affected phenotypic expression D) One allele was dominant
D
Within 6 months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were resistant to methicillin. These new S. aureus are known as MRSA. How can this best be explained? A) S. aureus evolved resistance to vaccines B) A patient must have become infected with MRSA from a different country C) In response to the drug, S. aureus began making drug resistant versions of itself D) Some drug resistant bacteria were present in the population at the start and natural selection increased their frequency.
D
True or False? Homologous structures are similar characteristics that represent a shared ancestor.
True
True or False? If the Hardy-Weinberg equation equals one, the population is not evolving.
False- if the allele frequencies of the population remain the same, year to year, the population is not evolving.
True or False? Artificial selection does not require heritable variation.
False; e.g. humans breed dogs to have short legs rather than long, or floppy ears instead of pointed up --> this is variation
True or False? An individual can evolve new traits in response to its environment.
False; evolution does not occur as a response, but as a mutation. These mutations may give advantage to organisms - these advantages lead the organism to reproduce more and more.
True or False? In a population there are only two alleles for every gene.
False; in an individual there are two alleles for every gene.
True or False? Mendel's "law of independent assortment" states that each pair of alleles or chromosomes segregates in a linked way during gamete formation (so that one egg has the entire set of chromosomes from the father and the other egg the entire set from the mother).
False; the genes are not linked.
True or False? Mendel's "law of segregation" states that pairs of alleles segregate into gametes (each gamete has one allele).
True
What are the assumptions of Hardy-Weinberg equilibrium?
Large population No sexual selection No genetic drift No mutations No gene flow
How does microevolution differ from macroevolution?
Microevolution can turn into macroevolution with many years. Microevolution is a change of allele frequencies within a population. Macroevolution is the evolution of large changes, such as the formation of wings, extra limbs and appendages.
Consider two species that diverged while geographically separated but resumed contact before reproductive isolation was complete. Predict what would happen over time if the two species mated indiscriminately and (a) hybrid offspring survived and reproduced more poorly than offspring from intraspecific matings or (b) hybrid offspring survived and reproduced as well as offspring from intraspecific matings.
The hybrid offspring would eventually die off assuming that no mutations (that give an advantage) would occur. The true breeding species who have a greater fitness (meaning that they contribute more offspring) would continue to produce. Eventually, reproductive isolations would form, and the species would no longer have the capability to mate.
Define Biological Population
one or more organisms of a species, interacting with one another in a set area or location
What is the Hardy-Weinberg equation?
p^2 + 2pq + q^2 = 1
