Biology Final Exam & Student Questions

In American alligators (Alligator mississipiensis) the allele for asymmetric stripes (A) is dominant to the allele for symmetric stripes (a). A researcher collects DNA samples and finds the following genotypes: 156 AA 98 Aa 258 aa What is the frequency of the recessive allele (a) in this population? Keep four decimal places while calculating your answer to avoid rounding error.

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In many species of bird, such as the Mallard duck seen below, males are brightly colored whereas females are drab in color. Which of the following best explains the existence of this sexual dimorphism (difference between males and females)? a) Intersexual Selection b) Genetic Drift c) Intrasexual Selection d) Different diets of males and females

A

Sugar gliders (left image) are a small gliding marsupial native to Australia. Flying squirrels (right image) are a small gliding placental mammal native to North America. The similar membranes that extend between these organisms' wrists and ankles to allow gliding over large distances were not inherited from a common ancestor. This is an example of what concept? a) Analogy b) Homology c) Introduced species d) Indicator species e) None of the above

A

The formation of the Grand Canyon geographically separated a species of antelope squirrel into two populations: one on the north rim and one on the south rim. Over many generations, the two populations have developed into two distinct species, the Harris's antelope squirrel (Ammospermophilus harrisii - pictured below) and the white-tailed antelope squirrel (Ammospermophilus leucurus). This is an example of what concept? a) Allopatric Speciation b) Sympatric Speciation c) Genetic Drift d) Migration

A

Which of the following is true? a) Dominant alleles decrease in frequency in a population faster than recessive alleles when selected against b) Recessive alleles decrease in frequency in a population faster than dominant alleles when selected against c) When recessive alleles are selected against they can not be removed from the population d) When dominant alleles are selected against they can not be removed from the population e) None of the above are true

A

A(n) ____________________ is a broad explanation of some aspect of the natural world that is supported by a large body of evidence. a) Hypothesis b) Theory c) Observation d) Scientific Method

B

Historically, human infants that have a very low birth weight lose heat quickly and become ill more easily, while infants that have a very high birth weight are very difficult to deliver. Infants with a medium birth weight are healthier and easier to deliver and so are more likely to survive (mortality for different birth weights depicted in the figure below). Which type of selection best describes this scenario? a) Directional Selection b) Stabilizing Selection c) Disruptive or diversifying selection d) All of the above options are possible

B

In comparing the nucleotide sequences of a given gene for three closely related species, you observe the following: species A and B differ at 5% of base pair positions within the gene sequence species A and C differ at 8% of base pair posiitons within the gene sequence species B and C differ at 3% of base pair positions within the gene sequence According to the molecular clock theory, this data can be used to support which of the following conclusions? a) the first species to diverge were A and B b) species B and C are more closely related to each other than to species A c) the most recently diverged species are species A and C d) All conclusions presented are correct e) No conclusions can be drawn from the given data

B

Missense Mutations, gene amplifications, chromosomal translocations, and retrovirus insertions are all mutations that convert ______ into ______ that may lead to cancer through increased gene activity and the promotion of uncontrolled cell division. a) Oncogene, Proto-Oncogene b) Proto-Oncogene, Oncogene c) Cyclins, Cyclin-dependent Protein Kinases (cdks) d) Cyclin-Dependent Protein Kinases (cdks), Cyclins

B

The central dogma of molecular biology states that: a) enzymes are used to lower the activation energy for chemical reactions in cells b) proteins contain information that is transcribed in RNA and translated into DNA c) genes contain information that is transcribed into mRNA, then translated into a protein. d) prokaryotic cells are more complex than eukaryotic cells because of combinatorial control of gene expression Concept addressed: Relationship between genes/genotype and proteins/phenotype A student needs to know what the Central Dogma is and which processes are involved in the creation of phenotype from genotype see also Brooker p. 238.

B

There are several factors that affect whether or not an organism will be preserved as a fossil, resulting in an incomplete fossil record of the history of life on earth. Which of the following organisms would you predict to be the MOST LIKELY to become fossilized? a) a soft-bodied organism with a limited terrestiral distribution b) a marine crustacean with a thick shell that lived over a long period of geologic time c) a small land-dwelling mammal that lived over a brief period of geologic time d) each of these organisms is equally likely to become fossilized

B

Which of the following is NOT considered one of the main characteristics of life? a) Reproduction b) Multicellularity c) Composed of cell(s) d) Responding to the environment

B

Which of the following is NOT necessary for evolution by natural selection to occur? a) Heritablity b) Sexual Reproduction c) Genetic variation in a population d) Selection e) All of the above are required for evolution by natural selection to occur

B

Which of the following statements is true regarding homologies? a) homologies between organisms are the result of convergent evolution selecting for similar adaptations in different lineages b) homologies between organisms are the result of inheritance of features from a common ancestor c) homologies between organisms are the result of analogous selection pressures in different but similar environments

B

Within a small population, a beneficial allele (gene variant) is present in only ~2% of the individuals in the population. Due to random changes in allele frequencies over a few generations, the rare beneficial allele is lost from the population. This example of a loss of genetic diversity in a small population is known as which of the following? a) Heterozygosity b) Genetic Drift c) Effective Population Size d) Biodiversity c) Natural Selection

B

A biologist wants to sample the height of bamboo plants in a tropical rain forest. For ease of data collection, the biologist randomly samples bamboo plants located around the edge of the rain forest. Is this an appropriate form of sampling? Why or why not? a) Yes; as long as the sample is random this will give a good average for the forest as a whole. b) Yes; the fact that travel in rain forests is difficult justifies the procedure. c) No; because the sampling occurred only at the edge and not across the forest, the sample will be biased. d) No; because to get the true average, every plant in the forest must be measured.

C

According to fossil evidence... a) the first life appeared on the earth between 3-4 million years ago b) the first life appeared on the earth between 30-40 million years ago c)the first life appeared on the earth between 3-4 billion years ago d) the first life appeared on the earth between 3,000-4,000 years ago

C

In the creation of ATP through respiration, what is the order respiration occurs in before it reaching the end of the cycle? a) Electron transport chain, glycolysis, creation of acetyl CoA, citric acid cycle. b) glycolysis, citric acid cycle, creation of acetyl CoA, electron transport chain. c) glycolysis, creation of acetyl CoA, citric acid cycle, electron transport chain. d) electron transport chain, creation of acetyl CoA, citric acid cycle, glycolysis Concept: Chapter 7. Page 137. One must know the process of respiration.

C

Which of the following statements is FALSE regarding endosymbiotic theory? a) Chloroplasts in present day eukaryotic cells are derived from bacteria that were independent organisms b) Eukaryotic cells contain multiple genomes c) Mitochondria in present day eukaryotic cells no longer contain any genes d) Mitochondria in present day eukaryotic cells are derived from bacteria that were independent organisms e) endosymbiotic theory is an example of horizontal gene transfer

C

Consider the following mRNA sequence mutation: Original mRNA sequence: 5' AUG CCG CGU GGU AAC GGG CUU 3' Mutated mRNA sequence: 5' AUG CCG CGC GGU AAC GGG CUU 3' If this mutation occurred in a proto-oncogene gene sequence, what would be the most likely outcome? a) loss of function of the proto-oncogene protein b) conversion of the proto-oncogene to a tumor-suppressor c) gain of function of the proto-oncogene protein d) no effect on function of proto-oncogene protein e) conversion of the proto-oncogene to an oncogene

D

In black bears (Ursus americanus), the allele for black fur (B) is dominant to the allele for brown fur (b). A researcher collects DNA samples from a northern Minnesota population of black bears and finds the following genotypes: 137 BB 98 Bb 359 bb If this population of black bears is in Hardy Weinberg Equilibrium, what would you expect would happen to the allele frequencies after several generations? a) The frequencies will change due to genetic drift b) The frequencies will change due to stabilizing selection c) The frequencies will be unchanged due to stabilizing selection d) The frequencies will be unchanged due to the absence of selection pressure, migration, or genetic drift

D

Which of these enzymes is mismatched with its function in DNA replication? a) topisomerase relieves supercoiling of DNA during unwinding of the helix b) single stranded binding protein stabilizes singe strands of DNA c) DNA polymerase synthesizes new polymers of DNA d) Primase creates a covalent bond between Okazaki fragments on the lagging strand

D

Would it be easier to prove the following statement true or false, and why? "All red insects have hard shells." It is easier to prove that the statement is: a) true because only one instance of a red soft shelled insect would be required b) true because it is impossible to prove a general rule with only limited evidence c) false because it is impossible to prove a general rule with only limited evidence d) false because only one instance of a red soft shelled insect would be required

D

A woman has a bacterial skin infection that is being treated with the antibiotic erythromycin. Bacteria with genetic variation that allow them to survive in the presence of the antibiotic become the only bacteria that survive the antibiotic treatment. What type of selection pressure is being demonstrated in this example? Explain why.

Directional Selection

What is cell theory? a) All living organisms are composed of one or more cells b) Cells are the smallest units of life c) New cells come only from preexisting cells by division d) None of the above e) All of the above f) A and B only General features of cells Chapter 4 specifically cell theory, page 66

E

Which of the following are observations of biological evolution? a) The traits of domesticated species have been modified by selective breeding. b) At the molecular level, certain characteristics are shared by all living cells, suggesting all living species are derived from a common ancestor. In addition, species that are more closely related to one another have more similar DNA sequences than distantly related organisms. c) Two different species from different lineages become anatomically similar because they occupy similar environments and natural selection promotes adaptation to a particular environment. d) Only 1 and 2 are observations of biological evolution. e) All of the above are observations of biological evolution.

E

Darwin's finches are a well-studied group of 15 bird species found on the Galapagos Islands. These species share a common finch ancestor that likely originated from the South American continent which migrated to the Galopogos and resulted in the diversification of many species on different islands with different habitats. The body size, the size and shape of their beaks, and mating songs are the most noticeable differences between the Galopogos finch species. The beaks in particular are very highly adapted to their food supplies, with each species having adapted to occupy a different niche on the islands. Darwin's finches are an example of which of the following concept(s)? a) Founder effect b) Behavioral reproductive isolation c) Adaptive radiation d) Options 1 and 2 are correct e) Options 1 and 3 are correct f) All of the above are correct

F

True / False : Darwin is credited with being the first person to come up with the theory of evolution.

F

Viruses are Alive. True or False

F

Western Meadowlarks and Eastern Meadowlarks have overlapping geographic distribution in central United States. These two species are phenotypically very similar and utilize similar habitats, but each has a distinct mating call. The different songs of meadowlarks is an example of which of the following? I. postzygotic reproductive isolation II. prezygotic reproductive isolation III. gametic reproductive isolation IV. mechanical reproductive isolation V. hybrid inviability VI. behavioral reproductive isolation a) Both I and III b) Both II and III c) Both I and IV d) Both II and IV e) Both I and V f) Both II and V g) Both I and VI h) Both II and VI

H