Directed Reading

Section: Genetic Variation

Read each question, and write your answer in the space provided.

1. What had Charles Darwin studied carefully that led him to develop the theory of evolution by natural selection?

2. Darwin knew about heredity, but what did he not know about it that we now know makes heredity possible?

3. Microevolution can be studied by observing changes in what?

4. What is a phenotype?

5. What is a polygenic character?

6. What is a gene pool?

Complete each statement by underlining the correct term in the brackets.

7. Darwin did not know about [heredity / genes].

8. Population genetics involves the study of [microevolution / population growth].

9. A physical characteristic of an organism is a [phenotype / genotype].

10. A character that is influenced by several genes is a [polygenic / genotypic] character.

11. A normal distribution histogram forms a [bell curve / straight line].

12. To study genetic variation, the number of [alleles / individuals] in a population must be estimated.

13. Mutation generates new alleles at a [slow / rapid] rate.

Complete each statement by writing the correct term or phrase in the space provided.

14. ______________________ ______________________ was the first person to observe and mathematically deduce the ration of alleles in an individual organism.

15. Genetic variation and change are measured in terms of the ______________________ of alleles in the gene pool of a population.

16. A line graph showing the general trends in a set of data of which most values are near the mean is a ______________________ ______________________.

17. Alleles combine to form ______________________ that, in turn, produce recognizable phenotypes.

18. The sum of allele frequencies for any one gene is ______________________.

19. The major source of new alleles in natural populations is mutation in ______________________

______________________.

20. Evolution cannot proceed if there is no ______________________ ______________________.

Section: Genetic Change

In the space provided, write the letter of the description that best matches each term.

1. genetic equilibrium 2. gene flow

3. nonrandom mating 4. genetic drift 5. mutation

6. natural selection 7. stabilizing selection 8. disruptive selection

In the space provided, explain how the terms in each pair are related to each other.

9. gene flow, genetic drift

10. mutation, natural selection

11. directional selection, stabilizing selection

a.the movement of alleles into and out of a population

b.one of the most powerful agents of genetic change c.eliminates individuals with average phenotype values

d.a change in allele frequency because of random occurrences

e.the state of a population in which no genetic change occurs

f.the mechanism that drives evolution

g.individuals show preferences in the choice of breeding partners

heliminates individuals that have alleles for any

extreme type

Read each question, and write your answer in the space provided.

12. What are the five forces of genetic change?

13. What does the Hardy-Weinberg principle predict?

14. Explain why natural selection does not act directly on genes.

15. Explain how sexual reproduction affects evolution.

16. What effect does nonrandom mating have on the frequency of alleles in a population?

17. Explain how natural selection is limited.

18. Describe directional selection and give an example.

19. Describe stabilizing selection.

20. What is disruptive selection?

Section: Speciation

In the space provided, write the letter of the description that best matches each term.

1. reproductive isolation 2. subspecies

3. divergence 4. speciation

5. adaptive radiation 6. hybrid

7. species 8. extinction

Read each question, and write your answer in the space provided.

9. To what kind of organisms can the biological species concept not be applied?

10. In what way does geography contribute to reproductive isolation?

a. the process of forming new species from preexisting species

b. generally, a group of natural populations that can interbreed

c. the divergence of multiple lineages into many new species in a specific area and time

d. a state in which a population can no longer interbreed with other populations

e. populations that have started speciation, having detectable divergence

f. offspring of two closely-related species g. the failure of a species to produce any more

descendants

h. an accumulation of adaptive differences

between populations

11. How does environmental change affect extinction?

Complete each statement by writing the correct term or phrase in the space provided.

12. Today, scientists may use more than one definition for ___________________.

13. The accumulation of differences, or ______________________, can lead to the formation of new species.

14. The process of forming new species by evolution from preexisting species is called ______________________.

15. If two populations stop ______________________, they take a step toward speciation.

16. Populations of species that are in ______________________ ______________________ may be subject to different selective forces and will tend to diverge over time.

17. If two populations develop differences in ______________________ behaviors, they may no longer attract each other for reproduction.

18. A ______________________ is a sterile hybrid of a horse and a donkey.

19. The species that exist at any time are the net result of both speciation and ______________________.

20. Extinction, like speciation, can be detected only after it is ______________________.

Section: The Importance of Classification

Complete each statement by writing the correct term or phrase in the space provided.

1. The practice of naming and classifying organisms is called ______________________.

2. Biologists use classification systems as a way to organize their ______________________ of organisms.

3. Linnaeus’s two-word system for naming organisms is called ______________________

______________________.

4. The two Latin-like terms in the name for a species is its ______________________

______________________.

5. The common name of Apis mellifera is ______________________ ______________________.

6. The Linnaean system of classification groups organisms on the basis of their form and ______________________.

7. Similar species are grouped in a taxonomic category called a(n) ______________________.

Complete each statement by underlining the correct term or phrase in the brackets.

8. The robin in Great Britain is [the same bird / a different bird ] from the robin in North America.

9. The scientific name is the two-part name for a [species / genus].

10. African lions are placed in the [species / genus] Panthera.

11. The largest category of modern classification is the [domain / kingdom].

12. The correct abbreviation of the scientific name for modern humans is

[H. sapiens / h.s.].

Study the following taxonomic categories. Determine the correct order of the categories from largest to smallest. Write the number of each category in the space provided.

13. phylum 14. class 15. species 16. family 17. order 18. kingdom 19. genus 20. domain

Read each question, and write your answer in the space provided.

21. How did biologists name a particular type of organism before the mid-1700s?

22. Explain how the genus and species name of an organism is properly written.

Section: Modern Systematics

In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.

1. The science of classifying organisms according to their relationships is a. systematics.

b. anatomy.

c. cladistics.

d. taxonomy.

2. Which modern group of animals do some scientists think of as a subgroup of dinosaurs?

a. fish b. mammals c. birds d. reptiles

3. The evolutionary history of a group of organisms is called its a. fossil evidence.

b. classification.

c. family tree.

d. phylogeny.

4. Convergent evolution happens when similarities evolve in a. closely related groups.

b. groups that live in different environments.

c. groups that have similar lifestyles.

d. members of the same species.

5. An example of an ancestral character shared by conifers and flowering plants is a. flowers.

b. seeds.

c. fruits.

d. cones.

6. Which is the name for a family tree made using cladistics?

a. clade

b. cladogram

c. phylogeny

d. morphology

7. A cladogram is based entirely on whether an organism has or does not have a(n)

a. derived character.

b. ancestral character.

c. analogous character.

d. homologous character.

In the space provided, explain how the terms in each pair differ in meaning.

8. ancestral character, derived character

9. cladistics, phylogeny

Read the question, and write your answer in the space provided.

10. What is the principle of parsimony?

Section: Kingdoms and Domains

Complete each statement by writing the correct term or phrase in the space provided.

1. Sponges were once classified as plants but are now classified as ______________________.

2. Organisms in the kingdom ______________________ are eukaryotic and have cell walls made of chitin.

3. Organisms in the kingdom ______________________ have no peptidoglycan in their cell walls and are prokaryotes.

4. Animals have no cells walls, are multicellular and heterotrophic, and are of the ______________________ cell type.

5. In the three-domain system, two domains have ______________________ cell structure.

6. The most abundant kind of organism on Earth are the ______________________.

7. Archeans that live in hot springs that exceed 100

C are called ______________________.

Complete each statement by underlining the correct term or phrase in the brackets.

8. Archaea [have / do not have] peptidoglycan in their cell walls.

9. Methanogens are found in [the mud of swamps / very salty lakes].

10. [Autotrophs / Heterotrophs] get nutrients from other organisms.

11. The kingdom [Eubacteria / Monera] is equivalent to the domain Bacteria.

12. Scientists think that eukaryotes evolved from some [bacteria / archaea].

13. Fungi are more closely related to [plants / animals] than any other kingdom.

14. [Monera / Protista] is known as the “leftover” taxon.

In the space provided, explain how the terms in each pair differ in meaning.

15. cellulose, chitin

16. unicellular, multicellular

Read each question, and write your answer in the space provided.

17. How did the invention of the microscope help the classification of organisms?

18. Where are bacteria found?