Biol 100 Exam 2 Questions

Why is the Archaea domain closer to Eukarya than Bacteria?

Genetically, the Archaea are more similar to Eukarya than Bacteria.

Which of the following statements apply to the founder effect?

It decreases genetic diversity and it is a type of genetic drift

What is the role of natural selection in evolution?

Natural selection leads to evolutionary change when individuals with certain characteristics have a greater survival or reproductive rate than other individuals in a population and pass on these inheritable genetic characteristics to their offspring.

Is evolution random?

Sometimes

True/False: Mutation results in rapid evolution.

Sometimes

Describe the biological species concept.

Species united by being reproductively compatible.

Explain how the three domains of life - Bacteria, Archaea, and Eukarya - are evolutionarily related to each other.

They all come from a common ancestor.

An ant population eats only one type of fungus. A severe drought wipes out all of this fungus in the ant's habitat. What is the *likely* outcome for the population?

This ant population will die off.

T or F, After DNA replication, sister chromatids are attached at the centromere

True

T or F, Alleles are alternative versions of a gene

True

T or F, An example of nondisjunction is when homologous chromosomes fail to separate during meiosis.

True

T or F, Chromosomes condense during the prophase of mitosis

True

True/False: Natural selection is the only mechanism of evolution that results in adaptations.

True

Ultraviolet light is essential for the formation of this vitamin.

Vitamin D

Do all individuals produce the same amount and kind of melanin?

While all humans have the same number of melanocytes (which produce melanin and determine skin color), those melanocytes produce different amounts and kinds of melanin.

Describe the broad pattern of human skin color evolution using the folate/Vitamin D hypothesis to explain selection acting on this trait.

a

An organism that is eukaryotic, multicellular, and has cell walls is

a plant or a fungus.

An organism that is eukaryotic and photosynthetic is

a plant or a protist.

An organism that is eukaryotic, heterotrophic, and lacks cell walls is

a protist.

If crossing over has taken place: a. The chromosomes involves will each be a mix of maternal and paternal DNA b. The individual must be homozygous c. The chromosomes involved will end up in the same gamete d. The cells that are formed will be genetically identical

a. The chromosomes involves will each be a mix of maternal and paternal DNA

The collection of _____ in a population constitutes that population's gene pool.

alleles

An allele is

an alternate version of a gene.

What is an effect of gene flow?

an increase in the variety of alleles within the gene pool of a population

If a cell with 12 chromosomes undergoes mitosis, the resulting cells will each have: a. 3 chromosomes b. 6 chromosomes c. 12 chromosomes d. 24 chromosomes

c. 12 chromosomes

Natural selection: a. results in organisms that are perfectly adapted to their environments. b. is a random process. c. increases the frequency of beneficial alleles. d. both B and C

c. increases the frequency of beneficial alleles.

A power line cut isolated 50 roly-polies (also known as pill bugs, potato bugs, sow bugs, and doodle bugs) from its original population of 15,000. In the next generation, the new population exhibits dramatic genetic differences from the original one. This is most likely because: a. members of a small population tend to die off more quickly, removing alleles from the gene pool. b. gene flow increases in a new environment. c. a small population is being artificially selected. d. by chance, the allele frequencies of the isolated roly-polies differed from those of the original population.

d. by chance, the allele frequencies of the isolated roly-polies differed from those of the original population.

ANY organism has higher fitness if it ___ compared to other members of its population a. is physically stronger b. is better able to obtain food c. has a better defense against predators d. has a larger number of healthy and fertile offspring e. is faster and more agile

d. has a larger number of healthy and fertile offspring

You notice some very tiny squirrels on campus, and you read in the news that tiny squirrels are able to sneak into buildings to steal food. Apparently micro-squirrels have become more common over the last few generations because they are able to support and raise more offspring than an ordinary-sized squirrel. Given this information, what is most likely true? a. Genetic drift has caused tiny squirrels to become more common. b. The tiny squirrels arrived in town due to migration. c. The lowered frequency of larger squirrels over generations is occurring by chance. d. These squirrels are tiny due to a bottleneck. e. Being tiny is currently adaptive in this population of squirrels.

e. Being tiny is currently adaptive in this population of squirrels.

Evolution by natural selection is a scientific theory, which means that it is: a. a speculative idea. b. a scientific explanation that remains untested. c. not well supported by prior tests and observations. d. likely to be disproved by new evidence. e. a conceptual framework that explains existing facts.

e. a conceptual framework that explains existing facts.

Phenotypes are generally the result of: a. only a single gene b. the environment c. multiple alleles d. two or more genes e. the combination of genotype, the environment and chance events

e. the combination of genotype, the environment and chance events

Ultraviolet light destroys which vitamin essential for cell division?

folate

Random changes in the allele frequency of a population between generations is the definition of

genetic drift

Which mechanism(s) *decrease* variation in a population?

genetic drift (bottleneck effect and founder effect)

Distinguish between a theory and a hypothesis.

hypothesis - an educated guess; must be testable and must be falsifiable theory - a scientific explanation, supported by evidence gathered over time A hypothesis is a guess that can be proven wrong but a theory is proven to be true by scientific evidence.

According to the Biological Species Concept, new species arise as a result of

increased reproduction.

Skin color is determined by the amount of _______ a person has in their skin.

melanin

Which mechanism(s) *increase* variation in a population?

mutation and gene flow/migration

This mechanism is NOT responsible for random changes in allele frequency in the gene pool of a population.

natural selection

The biological species concept defines a species

on the basis of the ability to mate and produce fertile offspring.

How do organisms that cannot physically move undergo gene flow/migration?

organisms can exchange genetic information through movement gammies and spores

Gene flow can be described as changes in allele frequency due to

populations mating with other populations.

Compare and contrast the structure of prokaryotic and eukaryotic cells.

prokaryotic - a (typically) unicellular organism whose cell lacks internal membrane-bound organelles and whose DNA is not contained within a nucleus - no internal membrane - no nucleus - divide by binary fission - Bacteria and Archaea eukaryotic - a unicellular or multicellular organism characterized by the presence of a membrane-enclosed nucleus and organelles - membrane - nucleus - undergo mitosis - Eukarya

Identify and explain the mechanisms of evolution.

random evolution: - mutation - a change in the DNA sequence of an organism - genetic drift - the random loss of alleles from a population and is most effective in small populations - gene flow - the movement of alleles from one population to the other adaptation: - natural selection - the process by which those traits that increase fitness become more common in a population over generations

Explain the difference between random and adaptive mechanisms of evolution.

random: adaptive: - depends on many environmental factors - depends on other genes in individual - depends on others in population

For evolution to occur, what must happen to a population's gene pool?

the frequency of alleles in a population's gene pool must change.

What is a genotype?

the genetic makeup of an individual

Natural selection is the idea that _____.

the natural environment selects for favorable traits and those favorable traits are passed on to the next generation of offspring.

Define gene pool.

the total collection of alleles in a population

Which of the following would help darker-skinned people who live in low-UV environments remain healthy?

vitamin D supplementation

Allele frequencies of a population can change by A. natural selection B. genetic drift C. mutations in the gene pool D. founder effect E. All of the above

*All of the above.* A. natural selection B. genetic drift C. mutations in the gene pool D. founder effect

Provide and discuss examples for the evidence of evolution.

*Homology - similarity in structure due to common ancestry Evidence for evolution can be found from diverse disciplines such as comparative anatomy, embryology, intermediate fossils, and experiments.

What is needed for natural selection to occur?

- Variation in traits among individuals of the population - Traits must be heritable - Variation in reproduction output among individuals in population

List at least five ways that two species may be reproductively isolated from each other.

.1. Ecologically - they are not in the same ecological area 2. Temporally - they do not mate at the same time 3. Behaviorally - they mate for their own species only 4. Mechanically - they are structurally different 5. Geographically - they are not in the same geographical area

Distinguish between the four major groups of Eukarya.

1. Protists 2. Plants 3. Animals 4. Fungi

Will a change in allele frequencies always result in a beneficial evolutionary change for the population?

A change in allele frequencies does not mean that a beneficial evolutionary change has happened. There may be shifts in allele frequencies that are neither beneficial nor harmful.

Which statement is true about all animals? A. They are all multicellular eukaryotic heterotrophs. B. They all have an endoskeleton and bilateral symmetry. C. They are all single-celled species that can make their own food. D. They all have segmented body parts. E. none of these

A. They are all multicellular eukaryotic heterotrophs.

Are bacteria or archaea more closely related to the eukaryotes?

Archaea are more closely related to Eukarya than they are to Bacteria based on ribosomal RNA sequence similarity.

Which of the following is an example of gene flow? A. selective breeding of dairy cows to produce animals that can live in tropical climates and yield higher volumes of milk B. the carriage of seeds between two separate urban forests by wildlife such as squirrels and rats that travel back and forth between the two C. cross-pollination by migrating honey bees between two geographically separate but genetically identical cotton fields D. the passage of a recessive disease-causing allele from one generation to the next without the physical appearance of disease E. the introduction of Burmese pythons, with no known predators or compatible mates, into the Florida Everglades

B. the carriage of seeds between two separate urban forests by wildlife such as squirrels and rats that travel back and forth between the two

Which statement is false about protists? A. Protists are a highly diverse group. B. Some protists are heterotrophic. C. Protists form a genetically distinct evolutionary group. D. Some protists are unicellular and others are multicellular. E. Protists can be classified as plant-like, animal-like, or fungus-like.

C. Protists form a genetically distinct evolutionary group.

Which of the following are types of nonadaptive evolution? A. natural selection B. bottleneck effect C. founder effect D. Both B and C E. A, B, and C

D. Both B and C B. bottleneck effect C. founder effect

Which of the following statements is FALSE? A. Homologous forelimbs are a result of common ancestry. B. The forelimbs of tetrapods have the same common ancestor. C. The human wrist is a structure that evolved in fish 375 million years ago. D. Comparative anatomy is the study of bone structure in all organisms. E. Variations in forelimb bone shape and function are evolutionary adaptations.

D. Comparative anatomy is the study of bone structure in all organisms.

The Biological Species Concept applies to all of the following organisms EXCEPT A. lichens B. unicellular fungi C. algae D. fossils E. humans

D. fossils

Is it adaptive to be able to extract oxygen from water?

Depends, sometimes adaptive

Which statement is false about fungi? A. Many fungi form mycelia of hyphae. B. Some fungi live on trees. C. Some fungi can live symbiotically with other organisms. D. Most fungi are multicellular, although some are unicellular. E. Most fungi get their nutrients by ingesting small pieces of other living organisms.

E. Most fungi get their nutrients by ingesting small pieces of other living organisms.

Describe the relationship between natural selection and evolution.

Evolution is a gradual change in the inherited traits of a population over many generations. Natural selection is a mechanism where the members of a population best suited to their environment have the best chance of surviving to pass on their genes. Natural selection is an adaptive form of evolution.

T or F, Evolution can only be observed in the fossil record

False

T or F, If two heterozygous individuals are crossed, all of the following offspring will be heterozygous

False

T or F, It is not currently possible for scientists to make changes to the DNA sequence in human cells

False

T or F, Mitosis takes place in your gametes, whereas meiosis takes place in your somatic cells.

False

T or F, Populations contain all the genetic variation they need to adapt to any changes in their environment

False

T or F: Skin cells contain information about skin color but not about muscle proteins

False

T or F: the phenotype always shows the recessive allele

False

Which is necessary for natural selection to proceed? A. generations reproducing over time B. a mechanism of inheritance C. acquisition of adaptations D. variation within a population E. all of the above

*All of the above* A. generations reproducing over time B. a mechanism of inheritance C. acquisition of adaptations D. variation within a population

Evolution A. is a change in allele frequencies in a population over time B. is a very well supported scientific theory C. can be random or result in adaptations D. all of the above E. none of the above

*All of the above* A. is a change in allele frequencies in a population over time B. is a very well supported scientific theory C. can be random or result in adaptations

Variations of human skin tone is driven by A. inheritance and survival. B. DNA variation in the population. C. natural selection. D. adaptations over time. E. All of the answers are correct.

*All of the answers are correct.* A. inheritance and survival. B. DNA variation in the population. C. natural selection. D. adaptations over time.

Protists are difficult to classify because A. some share features with plants but are not plants themselves. B. some share features with animals but are not animals themselves. C. some share features with fungi but are not fungi themselves. D. All of the answers are correct. E. None of the answers are correct.

*All of the answers are correct.* A. some share features with plants but are not plants themselves. B. some share features with animals but are not animals themselves. C. some share features with fungi but are not fungi themselves.

The diversity of organisms found in an area is directly related to A. the diversity of temperature. B. the diversity of elevation. C. the diversity of rainfall. D. the diversity of the physical terrain. E. All of the answers are correct.

*All of the answers are correct.* A. the diversity of temperature. B. the diversity of elevation. C. the diversity of rainfall. D. the diversity of the physical terrain.

What are the defining features of eukaryotes, members of the domain Eukarya?

- Autotroph vs Heterotroph - External vs Internal Digestion - Cell Wall vs No Cell Wall (Chitin, Cellulose) - Unicellular vs Multicellular

List and describe the mechanisms that can reproductively isolate different species and prevent them from interbreeding.

1. Ecologically - they are not in the same ecological area 2. Temporally - they do not mate at the same time 3. Behaviorally - they mate for their own species only 4. Mechanically - they are structurally different 5. Geographically - they are not in the same geographical area

List the four major groups of Eukarya along with their distinguishing characteristics.

1. Protists - *most broad: can be autotroph or heterotroph, can have internal and external digestion, can have a cell wall or no cell wall, can be unicellular or multicellular 2. Plants - autotrophs, cell wall (cellulose), multicellular 3. Animals - heterotrophs, cell wall, internal digestion, multicellular 4. Fungi - heterotrophs, cell wall, external digestion, multicellular

What are the requirements for natural selection to take place in a population?

1. Variance - individuals within a population have different characteristics/traits 2. Inheritance - offspring inherit traits from their parents 3. Competition - more offspring are produced than can survive, so offspring with traits better matched to the environment will survive and reproduce more effectively than others

How are a hypothesis and a theory different?

A hypothesis is narrow while a theory is broad.

Which statement about prokaryotes is FALSE? A. Prokaryotes are diverse. B. All prokaryotes are bacteria. C. Prokaryotes are usually single celled. D. Prokaryotes are found in two domains. E. Prokaryotes cannot be seen by the naked eye.

B. All prokaryotes are bacteria.

Select the statement that describes how fitness and natural selection interact to lead to adaptation. A. All the individuals in a population carry the same alleles such that the resulting traits are passed on throughout the population over time but with no change in their occurrence. B. Alleles well-suited to the environment increase the fitness of organisms, allowing for higher survival and reproduction so that the beneficial alleles are passed on to future generations and increase in incidence in the population over time. C. The traits of a population of organisms change over time, some making the organisms more suited to the environment and some making the organisms less suited to the environment. D. As an individual adapts to the environment over its lifetime, it acquires traits that increase fitness, which are then passed on to its offspring. E. Randomly occurring alleles that give organisms an advantage in the environment are not passed on to offspring because they are not heritable traits.

B. Alleles well-suited to the environment increase the fitness of organisms, allowing for higher survival and reproduction so that the beneficial alleles are passed on to future generations and increase in incidence in the population over time.

Which of the following statements about natural selection is TRUE? A. Natural selection is a random process. B. Natural selection acts on phenotypes that are controlled by genes. C. Natural selection adapts a species to its environment, but it is not the process by which new species evolve. D. Natural selection changes the frequency of alleles in an individual. E. Natural selection operates independently of the environment.

B. Natural selection acts on phenotypes that are controlled by genes.

All of the following are true of evolution, EXCEPT A. evolution leads to individuals with higher fitness than their predecessors. B. individuals adapt their genes to improve survival. C. the environment plays a large role in the process of evolution. D. individuals with the most adaptive phenotypes have the most offspring. E. evolution works through natural selection.

B. individuals adapt their genes to improve survival.

Which statement about evolution by natural selection is false? A. Natural selection allows organisms with higher fitness to reproduce more successfully. B. Evolution by natural selection affects populations of organisms, not individual organisms. C. Natural selection is a random change in allele frequencies over generations. D. Evolution by natural selection occurs more rapidly in organisms with high reproductive rates. E. Natural selection favors those traits that confer higher fitness in the environment.

C. Natural selection is a random change in allele frequencies over generations.

All of the following are TRUE of fungi, EXCEPT A. they can be single celled or multicelled. B. they are eukaryotic. C. they are autotrophs. D. they have cell walls made of chitin. E. they secrete digestive enzymes onto their food and then absorb the products.

C. they are autotrophs.

Select the scenario in which a mutation may become fixed in a population. A. A mutation causing light skin shows up in a population of people living near the equator in South America. B. A mutation for a stubby tail occurs in a population of Eastern gray squirrels, which normally have long, bushy tails. C. Several bacteria in a population resistant to the antibiotic erythromycin show susceptibility to erythromycin because of a recent mutation. D. A mutation occurs in a population of brown toads, causing green stripes that allow for better camouflaging in its habitat. E. In a population of people whose main food source is the milk of their livestock, a mutation for lactose intolerance appears.

D. A mutation occurs in a population of brown toads, causing green stripes that allow for better camouflaging in its habitat.

Both vitamin D and folate levels are affected by UV radiation from sunlight. Which of the following correctly explains the effects of sunlight on these vitamins? A. Both vitamin D and folate are degraded by UV radiation from sunlight. B. Sunlight is necessary for both vitamin D and folate formation. C. Sunlight degrades vitamin D but helps build folate. D. Sunlight degrades folate but helps build vitamin D. E. Moderate sunlight is necessary to build both vitamin D and folate, but excess sunlight degrades both.

D. Sunlight degrades folate but helps build vitamin D.

All of the following are TRUE of natural selection, EXCEPT A. the environment plays a large role. B. natural selection acts upon phenotypes that are controlled by genes. C. individuals with advantageous mutations will leave more offspring than those without the mutation. D. a mutation that is advantageous to an individual will be advantageous to all individuals in all environments. E. as a result of natural selection, allele frequencies in a population change.

D. a mutation that is advantageous to an individual will be advantageous to all individuals in all environments.

Which of the following populations is most likely to survive changing environmental conditions? A. a population of 50 individuals with low allelic diversity B. a population of 50 individuals with high allelic diversity C, a population of 1000 individuals with low allelic diversity D. a population of 1000 individuals with high allelic diversity E. allelic diversity does not matter, only the size of the population

D. a population of 1000 individuals with high allelic diversity

All of the following are true of genetic drift, EXCEPT: A. changes in allelic frequencies are always random. B. changes in allelic frequencies may benefit the population. C. changes in allelic frequencies may harm the population. D. genetic drift has the greatest influence on large populations. E. over time, genetic drift decreases the genetic diversity of a population.

D. genetic drift has the greatest influence on large populations.

Select the statement that correctly describes the evolutionary relationships among the domains of life. A. Archaea and Bacteria do not share a common ancestor with Eukarya. B. The genetic distances among Archaea, Bacteria, and Eukarya are about the same. C. Archaea and Bacteria are more closely related than Archaea and Eukarya. D. Archaea and Eukarya do not share a common ancestor with Bacteria. E. Archaea and Eukarya are more genetically similar than Archaea and Bacteria.

E. Archaea and Eukarya are more genetically similar than Archaea and Bacteria

Select the explanation for why a phenotype is selected for in the first environment but selected against in the second environment. A. The phenotype is found as a low percentage of the population in the first environment and is found as a high percentage in the second environment. B. The phenotype makes it difficult to secure resources in the first environment but provides access to resources in the second environment. C. The phenotype stands out to predators in the first environment but blends into the background in the second environment. D. The phenotype is caused by alleles that disadvantage the organism in the first environment but benefit the organism in the second environment. E. The phenotype leads to higher rates of survival and reproduction in the first environment but lower rates of both in the second environment.

E. The phenotype leads to higher rates of survival and reproduction in the first environment but lower rates of both in the second environment.

T or F, Humans have 23 different chromosomes and the number of possible different gametes is also 23.

False

What is the relationship between global UV light intensity and skin pigmentation?

High UV intensity is positively correlated with increased skin pigmentation

Genetic drift

How allele frequencies change: allele frequencies change due to change events Adaptive or nonadaptive?: nonadaptive Its effect on genetic diversity: decreases - alleles are eliminated from the population

Gene flow

How allele frequencies change: alleles move from one population to another Adaptive or nonadaptive?: nonadaptive Its effect on genetic diversity: increases - new alleles are added to the population

Natural selection

How allele frequencies change: individuals with favorable alleles reproduce preferentially, increasing the frequency of these alleles Adaptive or nonadaptive?: adaptive Its effect on genetic diversity: decreases - unfavorable alleles are eliminated from the population

Mutation

How allele frequencies change: new alleles are created randomly Adaptive or nonadaptive?: nonadaptive Its effect on genetic diversity: increases - new alleles are introduced into the population

What is a gene pool?

It refers to the total number of genes of every individual in a population. A large gene pool indicates high genetic diversity, increased chances of biological fitness, and survival.

Explain how melanin influences skin color.

Melanin is produced by skin cells when they are exposed to the sun. The more sun exposure, the more melanin is produced.

Can evolution by natural selection occur in the absence of genetic variation? Will it take place anytime genetic variation occurs? Explain.

Natural selection cannot occur in a population with no genetic variation. Pressure on the population from the environment will not lead to a change in allele frequencies because there were no differences in alleles to begin with. Natural selection does not necessarily occur anytime there is a population with genetic variation. For natural selection to occur, there has to be pressure from the environment to change the allele frequencies. If there is no pressure, there is no natural selection, even in the presence of genetic variation.

Does evolution and natural selection create perfect organisms?

No, environments are constantly changing which are constantly changing traits *natural selection is mindless, not goal oriented

Describe how the mechanisms of evolution influence genetic variation of a population.

Populations are constantly under the influence of the 4 mechanisms of evolution. They change the genetic makeup of organisms by either random chance or by adaptation. These mechanisms influence variation because there is no perfect way that an organism can or will change.

Which is a primary difference between all prokaryotes and eukaryotic cells?

Prokaryotes have DNA that floats freely in the cytoplasm.

Can the environment affect the amount of melanin produced in a person's skin? Explain.

Skin color and melanin adapt to intense sunlight irradiation to provide partial protection against the ultraviolet fraction that produces damage and thus mutations in the DNA of the skin cells. Those in warmer areas with more sun rays tend to be darker as opposed to those in less warm areas.

T or F, Migration of individuals into a population can increase the genetic variation in the population

True

T or F, Proto-oncogenes are normal genes with the potential to become oncogenes

True

T or F, Ultimate explanations address the question why natural selection has a favored particular trait

True

T or F, X-Linked traits often occur in different frequencies in males and females

True

True/False: Different versions of a gene are called alleles; a mutation in a gene can create an allele.

True

Can evolution by natural selection occur in the absence of differences in fitness among individuals in the population? Explain.

Without differences in fitness, natural selection cannot act and adaptation cannot occur.

Can different populations of the same organism have different gene pools? Why or why not?

Yes, different populations of the same organism can have different gene pools. Different populations of the same organism can be under different selection pressures depending on a variety of conditions. Physical location, for example, may cause different allele frequencies between the two populations.

Do you think the wing of a bird is homologous to the wing of a honeybee? Why or why not?

Yes, the similarities suggest the two species have been modified over time and come from the same ancestors.

Provide three examples for the evidence of evolution. Does homology apply to any of your examples?

a

What determines whether fitness varies among individuals (and if it occurs, which traits will be favored)?

a

What would be advantageous for reducing genetic bottleneck effects?

a large, genetically diverse population

A bottleneck is best described as

a reduction in the size of an original population followed by an expansion in size as the surviving members reproduce.

Which of the following statements is correct as the proximate cause for Gulf Coast Beach mice having blond fur? a. These mice had a gene mutation that produced a light pigment deposited in their fur. b. Natural selection changed the genes resulting in blond fur. c. In order to be camouflaged in the beach habitat a gene mutated to produce blond fur. d. Blond beach mice are camouflaged and less vulnerable to predation in a beach habitat. e. Answers A and C.

a. These mice had a gene mutation that produced a light pigment deposited in their fur.

An organism's fitness depends on its _____.

ability to survive and reproduce

What is a phenotype?

an individual's physical appearance and the genetic makeup of an individual

All animals are descended from a(n)

ancestral protist

If meiosis begins with a cell with 16 chromosomes, the resulting gametes will each have: a. 4 Chromosomes b. 8 chromosomes c. 16 chromosomes d. 32 chromosomes

b. 8 chromosomes

Which of the following is true about biological evolution? a. Evolution occurs within individuals. b. It is change in the frequency of an allele. c. It is change that occurs instantaneously. d. It is an informed statement of what might be true.

b. It is change in the frequency of an allele.

The phenotype of an organism is: a. Its genetic makeup b. Its physical characteristics c. A hypothesis of its evolutionary origins d. Both A and B

b. Its physical characteristics

Over the winter, you surveyed a population of American robins and determined that the frequency of an allele causing unusually white coloration is 2%. The population suddenly expands during the spring when many robins migrate back into the area. You survey the population again and find the frequency of that allele is now 1.5%. Has evolution occurred in the robin population? a. No, because there was no natural selection. b. Yes, because the allele frequencies in the population changed over time. c. No, because no mutation occurred. d. Yes, because the allele was not adaptive and decreased in frequency.

b. Yes, because the allele frequencies in the population changed over time.

50. What do the results above show about the role of predation and camouflage in beach mice? a. Predation on dark and light models is similar in both habitats. b. Camouflaged models suffer no predation in both habitats. c. Predation on camouflaged models is reduced relative to non-camouflaged models in both habitats d. White models reproduce faster in the field habitat than dark models.

c. Predation on camouflaged models is reduced relative to non-camouflaged models in both habitats

In order for a trait to be subject to the forces of evolution it must: a. be beneficial for the individuals with the trait b. be harmful for the individuals with the trait c. be passed on from one generation to the next d. be common

c. be passed on from one generation to the next

Many bacteria today are resistant to antibiotics that had previously been effective as treatments for infection. Antibiotic resistance has become more common because: a. antibiotics cause mutations in the DNA of bacteria that will make the bacteria resistant to the antibiotics. b. bacteria had to develop tolerance in order to survive. c. existing genetic variation caused some bacteria to be resistant to antibiotics, and those bacteria were more likely to survive and reproduce. d. All of the above are reasons for the increase in antibiotic resistance in bacteria.

c. existing genetic variation caused some bacteria to be resistant to antibiotics, and those bacteria were more likely to survive and reproduce.

Evolution may best be explained as a

change in the frequency of alleles in a population over time

Natural selection causes

changes in allele frequencies within a population

Mitosis is necessary for all of the following except: a. Growth b. Replacing warn out cells c. Repairing wounds d. Producing gametes

d. Producing gametes***

An organism's _________ determines its __________.

genotype; phenotype

Homology in comparative anatomy refers to

similarity of structure and a common ancestor