UNIT TEST 2 BIO 201
Which of the following is TRUE about the how the nature of science was used to make discoveries about Huntington's Disease? A. Dr. Huntington used observations of phenotypes in families to infer that the illness he studied was a genetic disease. B. Scientists compared normal brains and brains from patients with Huntington's Disease which allowed them to establish that the disease causes degeneration of some brain regions. C. A patient who has a huntingtin allele encoding 40 or more CAG repeats is virtually certain to develop Huntington's disease. This statement is like a theory. D. Dr. Wexler's work in the Lake Maracaibo region of Venezuela relied more on experiments, processes and causes than observations and patterns. E. All of the above are true.
A. Dr. Huntington used observations of phenotypes in families to infer that the illness he studied was a genetic disease.
The DNA molecules in cells of the pancreas (an organ in the digestive system) contain information relevant to which of the following? A. Eye color and pancreas function B. Eye color, but not pancreas function. C. Pancreas function, but not eye color. D. Neither eye color nor pancreas functio
A. Eye color and pancreas function
Which of the following statements is TRUE? A. There are many more new somatic mutations in an adult human than there are new germ-line mutations. B. Every human passes many somatic mutations to their offspring. C. Germ-line mutations in humans are usually beneficial. D. Germ-line mutations in humans are never beneficial. E. Every human inherits many somatic mutations from their parents.
A. There are many more new somatic mutations in an adult human than there are new germ-line mutations.
he scientific history of Huntington's Disease (HD) began with: A. a pattern B. a process C. a hypothesis D. a scientific law E. a scientific theory
A. a pattern
In the "switches" conceptual model of gene regulation, which things act as switches? A. noncoding DNA sequences B. messenger RNAs C. codons D. cells E. enzymes
A. noncoding DNA sequences
Which of the following is true about the parts of genes that code for amino acids? A. there may be differences in DNA sequences between alleles that do not cause differences in amino acid sequences between the alleles B. these parts of the gene are translated by the ribosomes but are not transcribed in the nucleus C. the function of the protein can be accurately determined by reading this part of the gene D. none of the above
A. there may be differences in DNA sequences between alleles that do not cause differences in amino acid sequences between the alleles
Which of the following statements is TRUE? A. Amino acids are converted into phenotypes through transcription and translation B. Amino acids influence how proteins fold and interact with the environment C. DNA nucleotides work with proteins to make the phenotype of the organism D. DNA nucleotides form a blueprint for the phenotype of the organism E. all of the above
B. Amino acids influence how proteins fold and interact with the environment
The study of "normal" brains and those of HD patients indicated... A. The brains of both types of patients showed no observable differences in the scans. B. HD brains were inferred to have more neuron death than normal brains. C. The study of the brains is best described as a causation study. D. HD causes atrophy of parts of the brain.
B. HD brains were inferred to have more neuron death than normal brains.
The mice used in the study of HD are best described as: A. Conceptual models B. Physical models C. Mathematical models D. They are not models
B. Physical models
Which of the following is TRUE about the huntingtin gene? A. Each variant of the huntingtin gene has the same number of CAG repeats. B. Some variants of the huntingtin gene are associated with Huntington's disease and some are not. C. The age at which Huntington's disease starts can be predicted exactly from a patient's huntingtin alleles. D. The huntingtin gene is only present in individuals with Huntington's disease.
B. Some variants of the huntingtin gene are associated with Huntington's disease and some are not.
Which of the following provides the closest analogy to the role of a gene in the cell? A. an architectural blueprint B. a set of instructions C. a 3D printer D. a brain E. a computer
B. a set of insturctions
A protein has the same amino acid sequence and the same function in two different species. Nevertheless, the protein may be present in different body parts in the two different species. What is the most likely direct explanation of this? A. the primary structure of the protein is different between the two species B. the gene encoding the protein is regulated differently between the two species C. the two species have different number of chromosomes D. the two species live in different environments
B. the gene encoding the protein is regulated differently between the two species
A protein is found in lung cells of an animal but not in brain cells of the same animal. What process most likely accounts for this? A. the gene encoding the protein is present in lung cells but not in brain cells B. the gene encoding the protein is transcribed in lung cells but is not transcribed in brain cells C. lung cells and brain cells differ in their ability to translate mRNAs into proteins D. all of the above are equally likely
B. the gene encoding the protein is transcribed in lung cells but is not transcribed in brain cells
Which of the following is the same between a person's fat cell and their blood vessel cell? A. the amounts of different proteins that are made B. the number of alleles that are in the nucleus of the cells. C. the types of proteins that are made D. the types of messenger RNA that are made
B. the number of alleles that are in the nucleus of the cells.
Dr. Huntington claimed that the illness in his patients was inherited. His claim is best described as: A. A law B. An observation C. An inference D. A theory
C. An inference
Which of the following is true about how genes influence phenotypes? A. Genes provide a perfect molecular blueprint for an organism's phenotypes. B. The phenotypic variation among humans largely results from their different genes. C. Genes code for proteins and proteins influence cell functioning. D. The genotypes of different individuals make different phenotypes.
C. Genes code for proteins and proteins influence cell functioning.
Which of the following is TRUE about mutations? A. Environmental conditions determine which mutations are most likely to occur. B. Mutations are rare in nature because the cell's DNA machinery repairs them. C. Most new mutations in an individual will not be inherited by its offspring. D. Toxic chemicals are a common cause of mutations in living organisms. E. Radiation is the most common cause of mutations in living organisms.
C. Most new mutations in an individual will not be inherited by its offspring.
Which of the following is a difference between a gene and an allele? A. A gene found on one copy of a single human chromosome is composed of multiple alleles. B. Organisms of the same species generally have the same alleles but often not the same genes. C. Organisms of the same species generally have the same genes but often not the same alleles. D. Genes code for proteins that impact cell function but alleles do not. E. Genes and alleles are basically the same thing.
C. Organisms of the same species generally have the same genes but often not the same alleles.
Which of the following statements about patterns and observations is TRUE? A. HD is an observation, not a pattern. B. Observations are generated from patterns. C. Patterns are generated from observations. D. Patterns and observations are the same thing. E. None of the above.
C. Patterns are generated from observations.
How could Tim (an adult human) have Huntington's disease even though neither of his parents have a Huntington's disease (HD) allele? A. Tim's HD allele could have originated during the production of one of his parents' somatic cells. B. Tim's HD allele could have originated during the production of one of his somatic cells after he became an adult. C. Tim's HD allele could have originated during the production of one of his parents' gamete cells. D. It is not possible for Tim to have an allele that neither of his parents have.
C. Tim's HD allele could have originated during the production of one of his parents' gamete cells.
Which of the following statements is incorrect? A. transcription uses DNA for information and results in the production of a mRNA B. translation uses mRNA for information and results in the production of a protein C. a DNA sequence change in the non-coding region of a gene could change the sequence of the encoded protein D. a DNA sequence change in the coding region of a gene could change the sequence of the encoded protein
C. a DNA sequence change in the non-coding region of a gene could change the sequence of the encoded protein
Which of the following is TRUE? A. the level of transcription is part of the information involved in regulation of a gene B. which cell types a gene is expressed in is part of the information involved regulation of a gene C. both A and B are true D. neither A nor B is true
C. both A and B are true
Which of the following is true about the keratin in human hair? A. each individual expresses only one allele of keratin in all of their hair cells B. each individual expresses only one keratin gene in all of their hair cells C. different levels of cysteine in the keratin affect the structure and properties of hair D. all of the above
C. different levels of cysteine in the keratin affect the structure and properties of hair
A person's genotype (i.e. a DNA sequence in their genome) can be highly predictive of a condition they will develop during life. This phenomenon is best described as a: A. theory B. hypothesis C. pattern D. law E. process
C. pattern
Which of the following statements is FALSE? A. Every human being carries somatic mutations. B. Every human being carries germ-line mutations. C. Every human being inherits germ-line mutations from each parent. D. Every human being inherits somatic mutations from each parent.
D. Every human being inherits somatic mutations from each parent.
Genetic information affects eye color. Where in the body would this genetic information be found? A. In the cells of the eye, but not in any other kind of body cell B. In the cells of the brain, but not in any other kind of body cell C. In the cells of the eye and the cells of the brain, but not in any other kind of body cell D. In all the different kinds of body cells
D. In all the different kinds of body cells
Which of the following is TRUE about the how the nature of science was used to make discoveries about Huntington's Disease? A. Dr. Huntington used observations on phenotypes in families to prove that the illness he studied was a genetic disease. B. Scientists compared normal brains and brains from patients with Huntington's Disease as physical models to establish that the disease causes degeneration of some brain regions. C. A patient who does not have a huntingtin allele encoding 40 or more CAG repeats is unlikely to develop Huntington's Disease. This statement is like a theory. D. None of the above are true.
D. None of the above are true.
The differences in the huntingtin gene that are associated with whether or not a patient will develop Huntington's Disease A. are found in the coding region of the gene B. affect the amino acid sequence of the encoded protein C. affect the primary and secondary structure of the protein D. all of the above
D. all of the above
Which of the following processes is involved with the explanation of how information in the keratin genes results in the phenotype of an animal's hair or fur? A. transcription B. translation C. protein structure D. all of the above E. none of the above
D. all of the above
Which of the following statements is TRUE? A. genes are sequences of DNA on chromosomes B. genes typically encode gene products C. genes contain information on their regulation D. all of the above
D. all of the above
The "HD gene" (huntingtin) was discovered in 1993. Did this discovery lead to a complete understanding of the cause of HD? A. yes, because an altered gene sequence is found to present in all HD patients B. yes, because an altered protein sequence is encoded by the gene in all HD patients C. no, because discovery of a contributing gene cannot contribute to knowledge of a disease caused by an altered protein D. no, because the functions of normal and altered Huntingtin proteins are still unclear
D. no, because the functions of normal and altered Huntingtin proteins are still unclea
Which of the following statements is TRUE? A. protein coding sequences are harder to find than transcriptional regulatory sequences because they are rare B. protein coding sequences are harder to find than transcriptional regulatory sequences because computer software cannot find them C. protein coding sequences are easier to find than trancriptional regulatory sequences because most of the genome codes for proteins D. protein coding sequences are easier to find than transcriptional regulatory sequences because they can be found using the genetic code
D. protein coding sequences are easier to find than transcriptional regulatory sequences because they can be found using the genetic code
When a biologist is talking about the level of gene expression, they are usually talking about: A. how strongly expressed a phenotype associated with the gene is B. how strongly reduced a normal trait is because of a mutation in the gene C. the number of genes that are involved in producing a trait D. the level of transcription of a gene E. none of the above
D. the level of transcription of a gene
A gene encoding an enzyme is transcribed in flower petal cells but is not transcribed in root cells of the same plant. What is the most likely explanation of this phenomenon? A. flower cells have the gene in their genomes but root cells do not have the gene in their genomes B. the gene has noncoding sequences that enable it to be transcribed in flower cells but prevent it from being transcribed in root cells C. flower cells have proteins that bind to noncoding sequences of the gene and help turn on transcription but root cells do not D. all of the above are true E. B and C are true but not A
E. B and C are true but not A
Which of the following is TRUE about mutations? A. Most healthy individuals have no mutations B. Most somatic mutations are harmful C. Mutations occur in germ-line cells, but not in somatic cells D. Mutations that occur in breast tissue cells can be passed on to offspring E. None of the above
E. None of the above
Which of the following statements is TRUE? A. All mutations can be considered deleterious to the individual. B. Organisms increase their mutation rates when the environment changes. C. Humans can pass on somatic mutations to their offspring. D. Most mutations present in a human's body are germ line mutations. E. none of the above
E. none of the above
Which of the following statements is correct? A. transcription uses RNA for information and produces a protein B. transcription uses DNA for information and produces a protein C. translation uses RNA for information and produces a mRNA D. translation uses DNA for information and produces a protein E. none of the above are correct
E. none of the above are correct
TRUE OR FALSE: The study of "normal" brains and those of Huntington's disease patients indicated that Huntington's disease causes atrophy of parts of the brain.
FA;SE
TRUE OR FALSE: A DNA sequence change in the non-coding region of a gene could change the sequence of the encoded protein.
FALSE
TRUE OR FALSE: A gene is generally expected to be transcribed at the same level in all of the cell types in which it is transcribed
FALSE
TRUE OR FALSE: A patient who does not have a huntingtin allele encoding 40 or more CAG repeats is unlikely to develop Huntington's Disease. This statement is like a theory
FALSE
TRUE OR FALSE: A patient who does not have a huntingtin allele encoding 40 or more CAG repeats is unlikely to develop Huntington's Disease. This statement is like a theory.
FALSE
TRUE OR FALSE: A protein is generally expected to be made in the same amounts in all of the cell types in which it is made
FALSE
TRUE OR FALSE: Amino acids are converted into phenotypes through transcription and translation
FALSE
TRUE OR FALSE: Both germ-line and somatic mutations can be passed on to offspring
FALSE
TRUE OR FALSE: CAG codes for glutamine, and glutamine is one of the amino acids in the mRNA
FALSE
TRUE OR FALSE: CAG repeats are located in the Huntingtin protein.
FALSE
TRUE OR FALSE: DNA nucleotides form a blueprint for the phenotype of the organism
FALSE
TRUE OR FALSE: Dr. Huntington observed that the disease was biologically inherited from parent to child.
FALSE
TRUE OR FALSE: Dr. Huntington used observations on phenotypes in families to prove that the illness he studied was a genetic disease.
FALSE
TRUE OR FALSE: Dr. Wexler's work in the Lake Maracaibo region of Venezuela relied more on experiments, processes and causes than observations and patterns
FALSE
TRUE OR FALSE: Environmental conditions determine which mutations are most likely to occur.
FALSE
TRUE OR FALSE: Huntington's disease is an observation, not a pattern.
FALSE
TRUE OR FALSE: Mice are often used in human disease research. In these studies, the mice are expected to respond to treatments in the same way as humans
FALSE
TRUE OR FALSE: Mice are often used in human disease research. In these studies, the mice represent human patients
FALSE
TRUE OR FALSE: Most mutations present in a human's body are germ line mutations.
FALSE
TRUE OR FALSE: Most somatic mutations are harmful.
FALSE
TRUE OR FALSE: Mutations in noncoding DNA can affect amino acid sequences of proteins
FALSE
TRUE OR FALSE: Noncoding DNA contains information that is directly relevant to the structure of proteins
FALSE
TRUE OR FALSE: Noncoding DNA contains information that is directly relevant to the structure of the prtoeisn
FALSE
TRUE OR FALSE: Protein coding sequences are easier to find than transcriptional regulatory sequences because most of the genome codes for proteins
FALSE
TRUE OR FALSE: Protein coding sequences are easier to find than transcriptional regulatory sequences because most of the genome codes for proteins.
FALSE
TRUE OR FALSE: Protein coding sequences are harder to identify than transcriptional regulatory sequences because computer software cannot find them
FALSE
TRUE OR FALSE: Radiation is the most common cause of mutations in living organisms.
FALSE
TRUE OR FALSE: Scientists compared normal brains and brains from patients with Huntington's Disease as physical models to establish that the disease causes degeneration of some brain regions.
FALSE
TRUE OR FALSE: Somatic cells have only one copy of each chromosome
FALSE
TRUE OR FALSE: The history of HD first began with inferences about people and their different phenotypes.
FALSE
TRUE OR FALSE: The sequence of DNA nucleotides in an organism's genome is a blueprint for the phenotype of the organism.
FALSE
TRUE OR FALSE: There are more germ-line cells in a person's body than somatic cells
FALSE
TRUE OR FALSE: Transcription uses RNA for information and produces a protein
FALSE
TRUE OR FALSE: Transcription uses RNA for information and produces a protein.
FALSE
B. About 20
Scientists measured the number of CAG repeats at the huntingtin gene for both alleles of 46 members of a population and plotted the results in the histogram shown. About how many distinct huntingtin alleles exist among these 46 subjects? A. ABOUT 5 b. ABOUT 20 c. ABOUT 50 D. about 100
TRUE OR FALSE: A mutation that results in a change in an amino acid in a protein may be harmful to the organism
TRUE
TRUE OR FALSE: Dr. Wexler's pedigree studies that took place in Venezuela are best described as association studies.
TRUE
TRUE OR FALSE: Every human being inherits germ-line mutations from each parent.
TRUE
TRUE OR FALSE: Mice are often used in human disease research. In these studies, the mice are a type of physical model
TRUE
TRUE OR FALSE: Mouse models were used to enhance understanding of how the HD gene causes the illness
TRUE
TRUE OR FALSE: Mutations can be neutral (not positive or negative) for an organism.
TRUE
TRUE OR FALSE: Mutations in somatic cells cannot be passed on to offspring.
TRUE
TRUE OR FALSE: Organisms usually have mutations in their germ-line cells that their parents do not have
TRUE
TRUE OR FALSE: Pedigree analysis involves making diagrams that can be used to infer hereditary processes.
TRUE
TRUE OR FALSE: Radiation is the most common cause of mutations in living organisms.
TRUE
TRUE OR FALSE: Risk of a disease is a phenotype.
TRUE
TRUE OR FALSE: Similarity in a phenotype between parent and offspring may not be due to inherited genetic factors.
TRUE
TRUE OR FALSE: Some non-coding DNA does not have a known function in the cell
TRUE
TRUE OR FALSE: The level of transcription is part of the information involved in regulation of a gene
TRUE
TRUE OR FALSE: The sequence of DNA nucleotides in an organism's genome provides information that is used by cells
TRUE
TRUE OR FALSE: There are many more new somatic mutations in an adult human than there are new germ line mutations
TRUE
TRUE OR FALSE: Transcription uses DNA for information and results in the production of a mRNA
TRUE
TRUE OR FALSE: Which cell types a gene is expressed in is part of the information involved regulation of a gene
TRUE
TRUE OR FALSE: mRNA encoded by the huntingtin gene is a gene product that is produced in individuals with and without HD
TRUE
TRUE OR FALSE: mRNA, proteins, and DNA sequences all influence phenotypes.
TRUE
B. This study is an example of an association study.
To make the graph above, researchers collected data from HD patients on the length of their longer huntingtin CAG repeat (of their two alleles) and the age of onset of the disease (the age at which disease symptoms started). Which of the following statements is TRUE? A.The graph shows that higher repeat numbers cause an earlier disease onset. B. This study is an example of an association study. C. Both A and B are true. D. Neither A nor B are true.
L1 LO1: Be able to explain how the following concepts from Unit 1 relate to the discovery and current understanding of Huntington's Disease: Observation, inference, pattern, process natural experiment, association study, Comparison study, physical model, conceptual model, Explanation, and process.
j
L1 LO2: Be able to identify two patterns from the history of research on HD and explain why they are best described as patterns and not processes
j
L1 LO3: Be able to compare and contrast the two types of models that have been used to advance understanding of the processes underlying HD
j
L1 LO4: Be able to build a conceptual model that uses observations, inferences, patterns, processes, models, and studies to explain why Huntington's disease occurs in some individuals and not others
j
L1 LO5: Be able to explain why single types of explanations—such as downward looking or functional explanations—cannot adequately account for phenomena such as HD
j