17.1 genes and variation name: biology date: period 17... · 1 17.1 genes and variation name:...

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17.1 Genes and Variation Name:

Biology Date: Period:

Genetics Joins Evolutionary Theory

Complete each statement by writing the correct word or words.

1. Natural selection works on an organism’s rather than its .

2. A(n) consists of all the genes, including the alleles for each gene, that are

present in a population.

3. A gene pool typically contains different for each heritable trait.

4. The number of times that an allele occurs in a gene pool compared with the number of times other alleles for

the same gene occur is called the of the population.

Use the circle graph of a sample mouse population to answer the following questions.

5. In the diagram below, use circles to represent the alleles within each segment of the population. Draw the B

alleles as solid circles and the b alleles as outline circles.

a. The total number of individuals in this population is ; the total number of alleles is .

b. How many alleles for black fur are in the sample population and what percentage of allele frequency

does that represent?

c. How many alleles for brown fur are in the sample population and what percentage of allele frequency

does that represent?

d. Describe how a geneticist might be able to tell that this population is evolving.

6. Can you determine whether an allele is dominant or recessive on the basis of the ratio of phenotypes in the

population? Explain your answer.

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Sources of Genetic Variation

7. What are mutations? When do they affect evolution?

8. How does sexual reproduction affect a population’s genetic variation?

9. Identify two ways in which genes can be recombined during meiosis.

10. Why is genetic variation important to the process of evolution?

Single Gene and Polygenic Traits

11. Label the two graphs to show which represents a single-gene trait and which represents a polygenic trait.

Write True if the statement is true. If the statement is false, change the underlined word or words to make the

statement true.

12. The number of phenotypes produced for a given trait depends on how many genes

control the trait.

13. Height in humans is an example of a single-gene trait.

14. Each gene of a polygenic trait often has two or more phenotypes.

15. A single polygenic trait often has many possible genotypes.

16. A symmetrical bell-shaped graph is typical of polygenic traits.

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Use the Venn diagram to compare and contrast single-gene traits and polygenic traits.

Concept Map A concept map helps you see how the topics you read about are related to one another. Use the

words and phrases below to fill in the empty spaces in the concept map.

Single-Gene Traits Both

Polygenic Traits

Genetic recombination Genes

Chromosomes Crossing-over

Sources of Genetic Variation

include

Mutations

involve changes in happens during

Lateral gene

transfer

Meiosis

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Single-Gene and Polygenic Traits

Polygenic Traits Some traits are controlled by only one gene. They are called single-gene traits. Other traits are

controlled by two or more genes. They are called polygenic traits. Human height is an example of a polygenic

trait.

1. Draw a curve connecting

the data points.

2. What shape is the curve you drew? a. bell curve b. one-sided curve c. irregular curve

3. What is the average height for this population?

a. 155–164 cm b. 165–174 cm c. 170–179 cm d. 185–194 cm

17.2 Evolution as Genetic Change in Populations

Term Definition

A change in an allele’s frequency following a dramatic reduction in population size

Form of natural selection in polygenic traits in which the entire curve shifts because some individuals are more successful at surviving

Form of natural selection in polygenic traits in which the curve splits in two because individuals at the two ends are more successful at surviving than those in the center

A change in an allele’s frequency that occurs as a result of a migration of a small part of the population

A random change in an allele’s frequency

When all of the alleles in a population remain the same

The process of selecting a mate based on traits like strength or color

Form of natural selection in polygenic traits in which the center of the curve stays in the same position because the individuals in the center are more successful at surviving

Height in

cm

Number of

Students

155–159 1

160–164 2

165–169 6

170–174 10

175–179 10

180–184 6

185-189 2

190–194 1

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How Natural Selection Works

1. If a trait made an organism less likely to survive and reproduce, what would happen to the allele for that

trait?

2. If a trait had no effect on an organism’s fitness, what would likely happen to the allele for that trait?

Use the table showing the evolution of a population of mice to answer the following questions.

Initial Population Generation 10 Generation 20 Generation 30

90% 80% 70% 40%

10% 20% 30% 60%

3. Is the trait for fur color a single-gene trait or a polygenic trait? Explain your answer.

4. Describe how the relative frequency of fur color alleles is changing in this population and propose one

explanation for this change.

5. Suppose a mutation causes a white fur phenotype to emerge in the population. What might happen to the

mouse population after 40 generations?

6. What effect does stabilizing selection have on variation in a population?

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Natural Selection on Polygenic Traits In most populations, a trait that has higher fitness leads to greater

numbers of organisms with that trait. The solid lines show the population after selection has taken place. Label

the graphs as disruptive selection or stabilizing selection.

__________________________ __________________________

7. With which type of selection do organisms in the middle of the curve have the highest fitness?

8. In disruptive selection, organisms on which part of the curve have the lowest fitness?

9. How does the curve change in stabilizing selection? The curve

a. becomes shorter and wider.

b. becomes taller and narrower.

c. moves to the right.

10. The plants in an area have either very small or very large seeds. Birds with small beaks can eat small seeds,

and birds with large beaks can eat large seeds. Birds with smaller beaks and birds with larger beaks become

more common than birds with medium beaks. What type of selection is this?

a. stabilizing selection b. disruptive selection c. directional selection

Genetic Drift – Use what you know about the Hardy-Weinberg principle to identify what is happening.

11. Genetic drift strongly affects the population.

a. small population

b. random mating

c. no movement into or out of the population

d. no natural selection

12. Lions with a darker fur color have the same chance to reproduce as lions with a lighter fur color.

a. large population

b. random mating

c. no mutations


13. Fitness is basically the same among individuals in the population.

a. large population

b. random mating

c. no mutations


14. In small populations, random changes in is called genetic drift.

15. A situation in which allele frequencies change as a result of the migration of a small subgroup of a

population is known as the .

16. The is a change in allele frequency following a dramatic reduction in

the size of a population.

Pe

rce

nta

ge

of

Hu

ma

n P

op

ula

tio

n original

population

Birth Weight Beak Size

Nu

mb

er

of

Bir

ds

in

Po

pu

lati

on

original

population

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Genetic Drift

Bottleneck Effect

caused by caused by

can result from

Complete the concept map.

Evolution Versus Genetic Equilibrium

17. What does the Hardy-Weinberg principle state?

18. What is genetic equilibrium?

19. Use phrases in the word box to identify each condition that leads to genetic equilibrium.

The Hardy-Weinberg Principle

The more individuals in the population, the smaller the effect of genetic drift.

No changes to genes means new alleles are not introduced into the population’s gene pool.

Each individual in a population has the same chance of passing on its alleles.

No new alleles are introduced into the population’s gene pool by new individuals.

No phenotype can have a selective advantage over another—all individuals have equal fitness.

20. Explain how sexual selection results in non-random mating.

large population no natural selection no movement

random mating no mutations

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21. Suppose a population of insects live in a sandy habitat. Some of the insects have tan bodies and some have

green bodies. Over time, the habitat changes to a grass-filled meadow. Use the ideas of natural selection to

explain how and why the insect population might change.

17.3 The Process of Speciation

Isolating Mechanisms

1. What is speciation?

2. What does it mean for two species to be reproductively isolated from each other?

3. What must happen in order for a new species to evolve?

4. Many finch characteristics appear in bell-shaped distributions typical of traits.

5. The ancestors of the Galápagos Island finches originally came from the continent of

.

6. The populations of finches on separate islands are isolated from one another by

large stretches of open water.

Populations Become Isolated - Read the chart below. Then, use phrases in the word box to identify each

process that leads to speciation.

Process How It Leads to Speciation

A population arrives in a new place.

Populations are separated by a geographic barrier and do not

share a gene pool.

Populations evolve new traits in response to natural selection

in their environments.

Species evolve in a way that reduces competition between

them.

Groups within a population are separated by different

courtship rituals.

changes in the gene pool geographic isolation founders arrive

competition behavioral isolation

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Speciation in Darwin’s Finches - Charles Darwin proposed that the different species of finches on the

Galapagos Islands once had a common ancestor. Over time, he said, natural selection led to each species of

finch. A current hypothesis says that speciation in the Galapagos finches occurred through the founding of a

new population, geographic isolation, changes in the new population’s gene pool, behavioral isolation, and

ecological competition. Use the phrases in the box to complete the chart.

Galápagos Islands Finches

Shape of

head and

beak

Main food

Feeding

adaptation Parrot-like beak uses cactus spines

pointed crushing

beak large crushing beak

Habitat trees trees ground ground

7. How does the large crushing beak help the fourth finch survive?

8. Circle the finch that would be least likely to survive if the insect population decreased.

9. Both the first and second finch live in trees. Suppose one season there is less fruit in the trees. Which finch

is more likely to survive and reproduce?

Populations Become Isolated

Speciation occurs when a new species evolves. Many things contribute to speciation. Read the chart below and

use phrases in the word box to identify each process that leads to speciation.

Process How It Leads to Speciation

A population arrives in a new place.

Populations are separated by a geographic barrier and do not share a gene

pool.

Populations evolve new traits in response to natural selection in their

environments.

Species evolve in a way that reduces competition between them.

Groups within a population are separated by different courtship rituals.

insects that live inside dead wood fruits large, thick-shelled seeds small seeds

changes in the gene pool geographic isolation founders arrive

competition behavioral isolation

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10. Finches prefer to find mates with the same size beaks. Finches in Group A have larger beaks than those in

Group B, so finches from the two groups will not mate. What is this an example of?

11. Do populations that are geographically isolated from one another share a gene pool? Why or why not?

12. Complete the table with the correct terms.

Term Definition

The number of times an allele appears in a gene pool, compared to

the total number of alleles in that pool for the same gene.

A common group of genes, and all their alleles, shared by a

population

A trait controlled by two or more genes

A trait controlled by only one gene

A change in an allele’s frequency following a dramatic reduction in

population size

Form of natural selection in polygenic traits in which the entire curve

shifts because some individuals are more successful at surviving

Form of natural selection in polygenic traits in which the curve splits

in two because individuals at the two ends are more successful at

surviving than those in the center

A change in an allele’s frequency that occurs as a result of a

migration of a small part of the population

A random change in an allele’s frequency

When all of the alleles in a population remain the same

The process of selecting a mate based on traits like strength or color

Form of natural selection in polygenic traits in which the center of

the curve stays in the same position because the individuals in the

center are more successful at surviving

When two populations have different behaviors that keep them from

reproducing

When two populations are separated by geographic features, such as

rivers or mountains, that keep them from reproducing

Separation of populations so that they cannot reproduce

A population or group of populations whose members can interbreed

and produce fertile offspring

The forming of a new species

When two populations reproduce at different times, so that they

cannot reproduce together

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Types of Natural Selection

A group of snakes were all placed into environments that had differing selective pressures. Read the data tables

below and graph each snake in its environment. From the graph, determine what type of selection is being

portrayed: directional, stabilizing or disruptive.

1. Snakes were placed on an island where there are two predators that eat snakes.

Number of Snakes at Each Length

2 cm 4cm 6 cm 8 cm 10 cm

Year

2000 2 14 18 12 4

2004 4 12 8 9 8

2008 10 6 3 6 14

2. Snakes were placed on an island where there is only one size of burrow available to the snakes to live in.



Year

2000 4 12 16 10 3

2004 3 10 18 9 3

2008 1 6 24 2 1

Graph is on the next page.

Type of Selection:

Summarize what happened

to the snakes.

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3. Snakes placed on an island where there is only one predator, a snake eating toad. This

toad can only eat snakes under 6 cm long.



Year 1980 4 12 14 8 12

1984 2 6 9 12 14

1988 1 2 2 15 18

Type of Selection:


to the snakes.

Type of Selection:


to the snakes.

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Types of Natural Selection

1. Limpets are marine organisms that have shells that vary in color from white to dark brown. Limpets live

their adult life attached to rocks. On light colored rock, white shelled limpets are at an advantage because

the birds that prey upon them have a difficult time locating them. On dark-colored rock, dark-shelled

limpets are well camouflaged. On the other hand, tan-colored limpets are easily spotted on either light or

dark rocks.

Name the type of selection: _____________________________________________

Explain why this type of selection occurred:

__________________________________________________________________________________________

__________________________________________________________________________________________

2. In spiders, the average size is at an advantage in terms of survival and reproduction. Large spiders are

easily seen and captured by their predators. Smaller than average spiders cannot catch enough prey to

survive.

Name the type of selection: ______________________________________________


__________________________________________________________________________________________

__________________________________________________________________________________________

3. Woodpeckers feed by pecking holes in trees in order to get at the insects living under the bark. One year,

the trees are invaded by insects that live deep within the trees. Woodpeckers with short beaks can’t reach

insects and starve. Only the woodpeckers with long beaks can eat and survive.

Name the type of selection: ______________________________________________


__________________________________________________________________________________________

__________________________________________________________________________________________

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4. In crossbills, a finch-like bird that lives in mountain forests, bill size is directly related to the size of seeds

that are eaten. Small seeds are eaten by birds with small bills while large seeds are eaten by birds with large

bills. Birds with a bill of intermediate size feed on seeds

of intermediate size.

A specific population of crossbills has a distribution

similar to the one at the right. Questions # a-d present

four types of environmental change that might impact

this population. For each potential change, choose the

distribution below that best suggests how this population

of crossbills would adjust. Compare each question

separately to the original starting population at the right. Any of the distributions (A-E) may be used once,

more than once, or not at all.

_____ a. Over a 10-year period, various species of seed-eating ants invade the area and disproportionately

consume a much greater number of intermediate-sized seeds.

_____ b. For 15 growing seasons colder than normal temperatures gradually favor the production of larger

seeds while plants producing smaller seeds do not survive and reproduce as well.

_____ c. A new species of finch, with a bill-size distribution similar to that of the crossbills, moves in to

the area. If combined onto one graph, which would be the most likely graph?

_____ d. Unidentified environmental factors, acting through natural selection, decrease the amount of

variation in bill size among the crossbills.

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Population Genetics and Hardy-Weinberg Genetic Equilibrium Name:

Evolution Date: Period:

The Hardy-Weinberg formulas allow scientists to determine whether evolution has occurred. Any changes in

the gene frequencies in the population over time can be detected. The principle states that if no evolution is

occurring, then equilibrium of allele frequencies will remain in effect in each succeeding generation of sexually

reproducing individuals. In order for equilibrium to remain in effect (i.e.no evolution is occurring) then the

following five conditions must be met:

1. No mutations must occur so that new alleles do not enter the population.

2. No gene flow can occur (i.e. no migration of individuals into, or out of, the population).

3. Random mating must occur (i.e. individuals must pair by chance).

4. The population must be large so that no genetic drift (random chance) can cause the allele frequencies to

change.

5. No selection can occur so that certain alleles are not selected for, or against.

Obviously, the Hardy-Weinberg equilibrium cannot exist in real life. Some or all of these types of forces all act

on living populations at various times and evolution at some level occurs in all living organisms. The Hardy-

Weinberg formulas allow us to detect some allele frequencies that change from generation to generation, thus

allowing a simplified method of determining that evolution is occurring. There are two formulas that must be

memorized:

p2 + 2pq + q2 = 1 and p + q = 1 (frequency of AA) + (frequency of Aa) + (frequency of aa) = 100%

p = frequency of the dominant allele in the population

q = frequency of the recessive allele in the population

p2 = percentage of homozygous dominant individuals

q2 = percentage of homozygous recessive individuals

2pq = percentage of heterozygous individuals

Example for Hardy Weinberg Equation

Albinism is a rare genetically inherited trait that is only expressed in the phenotype of

homozygous recessive individuals (aa). The most characteristic symptom is a marked deficiency in the skin and

hair pigment melanin. This condition can occur among any human group as well as among other animal

species. The average human frequency of albinism in North America is only about 1 in 20,000.

Referring back to the Hardy-Weinberg equation (p² + 2pq + q² = 1), the frequency of homozygous recessive

individuals (aa) in a population is q². Therefore, in North America the following must be true for albinism:

By taking the square root of both sides of this equation, we get:

In other words, the frequency of the recessive albinism allele (a) is .00707 or about 1 in 140. Knowing one of

the two variables (q) in the Hardy-Weinberg equation, it is easy to solve for the other (p).

The frequency of the dominant, normal allele (A) is, therefore, ________________ or about 99 in 100.

The next step is to plug the frequencies of p and q into the Hardy-Weinberg equation:

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This gives us the frequencies for each of the three genotypes for this trait in the population:

p² = predicted frequency of homozygous

dominant individuals

2pq = predicted frequency of heterozygous

individuals

q² = predicted frequency of homozygous

recessive individuals (albinos)

With a frequency of ____________ (about 1 in 20,000), albinos are extremely rare. However, heterozygous

carriers for this trait, with a predicted frequency of ____________ (about 1 in 72), are far more common than

most people imagine. There are roughly 278 times more carriers than albinos. Clearly, though, the vast

majority of humans ____________ probably are homozygous dominant and do not have the albinism allele.

PROBLEM #1 - View the Dragons on the right. The winged

trait is dominant.

Frequency

q2 (aa) =

q (a) =

p (A) =

p2 (AA) =

2pq (Aa) =

What is the frequency (%) of the heterozygote dragons in the

population.

PROBLEM #2

You have sampled a population in which you know that the percentage of the homozygous recessive genotype

(aa) is 36%. Using that 36%, calculate the following:

A) The frequency of the "aa" genotype.

B) The frequency of the "a" allele.

C) The frequency of the "A" allele.

D) The frequencies of the genotypes "AA" and "Aa."

E) The frequencies of the two possible phenotypes if "A" is completely dominant over "a."

PROBLEM #3

Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 40% of all

butterflies are white. Given this simple information, calculate the following:

A) The percentage of butterflies in the population that is heterozygous.

B) The frequency of homozygous dominant individuals.

PROBLEM #4

The ability to taste PTC is due to a single dominate allele "T". You sampled 215 individuals in biology, and

determined that 150 could detect the bitter taste of PTC and 65 could not. Calculate all of the potential

frequencies.

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Biology Keystone Exam Preparation

Natural Selection and Evolution

Keystone Eligible Content:

Explain how natural selection can impact allele frequency of a population

Describe the factors that can contribute to the development of new species (e.g. isolating mechanisms,

genetic drift, founder effect, migration)

Explain how genetic mutations may result in genotypic and phenotypic variations within a population

Distinguish between stabilizing, disruptive and direction selection.

Interpret evidence supporting the theory of evolution (i.e. fossil, anatomical, physiological, embryological,

biochemical, and universal genetic code)

Distinguish between the scientific terms: hypothesis, inference, law, theory, principle, fact, observation

1. Identify the type of selection in graph A _______________________________

2. Identify the type of selection in graph B _______________________________

3. Identify the type of selection in graph C _______________________________

4. In a species of snail, dark individuals are better hidden (from bird predators) in the shady forest, while

lighter individuals are better hidden in well lit brushy edge areas. There are no areas of intermediate

brightness; therefore, ___________ acts on shell color in these snails.

A. directional selection B. disruptive selection C. stabilizing selection

5. Small Aristelliger lizards have difficulty defending territories, but large lizards are more likely to be preyed

upon by owls. This situation results in ________ on adult body size.


6. Long necks make it easier for giraffes to reach leaves high on trees, while also making them better fighters

in "neck wrestling" contests. In both cases, __________ appears to have made giraffes the long-necked

creatures they are today.


7. Populations of the same species of seal live on islands too far apart to swim between them for mating.

A. behavioral isolation B. temporal isolation C. geographic isolation

8. Species of birds have elaborate courtship dances, and females select the best dancers as mates.


A B C

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9. Varieties of oak tree produce pollen during different seasons, so they can’t pollinate one another.


10. Herds of caribou misinterpret each other’s mating behavior, so they fight instead of mating.


11. The frequency of an allele in a fly population changes from 89% to 20% after three generations. Which

other events most likely occurred during the same time period?

A. An environmental change and a fly population increase.

B. An environmental change and a fly population decrease.

C. Interbreeding of flies with an invasive species and fly population speciation.

D. Interbreeding of flies with an established local species and fly population speciation.

Use the graph below to answer question 12.

12. Tail length in mice varies within a population. Scientists observed change in the distribution of tail lengths

in a mouse population over time. At the genetic level, what has most likely happened to the allele for the

shortest tail lengths?

A. The allele changed from being dominant to being recessive.

B. The allele changed from being autosomal to being sex-linked.

C. The allele became less frequent than the alleles for longer tail lengths.

D. The allele began to code for long tail lengths instead of the shortest ones.

Use the circle graphs below to answer question 13.

13. The graphs illustrate change in a lizard population over time. Which process most likely led to the change

in the lizard population?

A. natural selection acting on a harmful trait

B. natural selection acting on a beneficial trait

C. natural selection acting on a dominant trait

D. natural selection acting on a recessive trait

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14. In North America, the eastern spotted skunk mates in late winter, and the western spotted skunk mates in

late summer. Even though their geographic ranges overlap, the species do not mate with each other. What

most likely prevents these two species from interbreeding?

A. habitat isolation C. geographic isolation

B. gametic isolation D. reproductive isolation

15. A mutation occurs in the genes that code for coat color in deer. Which change will most likely result from

this mutation?

A. A change in the selection pressures acting on coat color.

B. A change in the coat-color genes of deer predator species.

C. An increase in coat-color diversity in the population.

D. An increase in the number of genes for coat color in the population.

Use the illustrations below to answer the next question.

16. The skeletons of mammalian forelimbs represent variations of a structure that was present in their common

ancestor. What has most likely caused the variation in forelimbs?

A. changes in muscle structure C. trait formation due to behaviors

B. changes in the genetic codes D. development of vestigial structures

17. A population of animals is permanently split by a natural barrier into two separate populations in different

environments. What will likely result after a long period of time?

A. The evolution of the two populations will be identical.

B. The production of variations will stop in the two populations.

C. The two populations will evolve into separate species.

D. Autotrophic nutrition will replace heterotrophic nutrition in the two populations.

18. When changes occur in the genes of sex cells, these changes

A. lead to mutations in the parent organism.

B. are always harmful to the offspring.

C. can be the basis for evolutionary change.

D. only affect sexually reproducing organisms.

19. When a species includes organisms with a wide variety of traits, it is most likely that this species will have

A. a high proportion of individuals immune to genetic diseases.

B. a greater chance to survive if environmental conditions suddenly change.

C. less success competing for resources.

D. limitless supplies of important resources, such as food and water.

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20. The sorting and recombination of genes during reproduction is important to evolution because these

processes

A. decrease variation and help maintain a stable population.

B. increase variation that enables species to adapt to change.

C. decrease the chances of producing offspring that are adapted to the environment.

D. increase the ability of all the offspring to adapt to the environment.

21. In the early stages of development, the embryos of dogs, pigs, and humans resemble one another. This

observation suggests that these animals may have

A. a similar number of chromosomes. C. the same blood components.

B. similar habitat requirements. D. a common ancestry.

22. The idea that evolution takes place at a continuous but very slow rate is known as

A. succession. C. punctuated equilibrium.

B. artificial selection. D. gradualism.

23. Which statement is best supported by the theory of evolution?

A. Genetic alterations occur every time cell reproduction occurs.

B. The fossil record provides samples of every organism that ever lived.

C. Populations that have advantageous characteristics will increase in number.

D. Few organisms survive when the environment remains the same.

24. Differences between the members of a population will most likely be passed to future generations if they are

A. due to genetic changes and result in unfavorable variations.

B. due to genetic changes and result in favorable variations.

C. not due to genetic changes and result in unfavorable variations.

D. not due to genetic changes and result in favorable variations.

25. A gene pool consists of

A. all the genes that mutate in a single generation.

B. all the heritable genes for traits in a population.

C. all the gametes produced by a population.

D. the mutated alleles for a particular trait.

26. A characteristic that an organism exhibits during its lifetime will only affect the evolution of its species if

the characteristic

A. results from isolation of the organism from the rest of the population.

B. is due to a genetic code that is present in the gametes of the organism.

C. decreases the number of genes in the body cells of the organism.

D. causes a change in the environment surrounding the organism.

27. A researcher recently discovered a new species of bacteria in the body of a tubeworm living near a

hydrothermal vent. He compared the DNA of this new bacterial species to the DNA of four other species of

bacteria. The DNA sequences came from the same part of the bacterial chromosome of all four species.

According to these data, the unknown bacterial species is most closely related to

A. species I

B. species II

C. species III

D. species IV

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28. Which species in the chart below is most likely to have the fastest rate of evolution?

29. The gene COII is in the genome of many organisms. A comparison of the number of base differences

between the COII gene in a rat and that of two other animals is shown.

A. Based on the data, describe a possible evolutionary relationship between rats, mice, and cows.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

B. Describe how different organisms having a common gene such as COII supports the theory of evolution.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

C. The COII gene of a monkey has 203 base differences from the same gene in a rat and 201 base differences

from the same gene in a mouse. Compare the evolutionary relationships between the monkey, the rat, and

the mouse.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

17.1 genes and variation name: biology date: period 17... · 1 17.1 genes and variation name:...

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