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WorksheetsAP Biology Unit 6 Genetics Review Quiz
Total questions: 13
Worksheet time: 7mins
Erwin Chargaff investigated the nucleotide composition of DNA. He analyzed DNA from various organisms and measured the relative amounts of adenine (A), guanine (G), cytosine (C), and thymine (T) present in the DNA of each organism. Table 1 contains a selected data set of his results.
Which of the following statements best explains the data set?
Since the %A and the %G add up to approximately 50 percent in each sample, adenine and guanine molecules must pair up in a double-stranded DNA molecule.
Since the %A and the %T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule.
Since the %(A+T) is greater than the %(G+C) in each sample, DNA molecules must have a poly-A tail at one end.
Since the %C and the %T add up to approximately 50 percent in each sample, cytosine and thymine molecules must both contain a single ring.
Antibiotics can be used to kill the specific pathogenic bacterium, Mycobacterium tuberculosis, that causes tuberculosis. The appearance of antibiotic-resistant strains has made it more difficult to cure M. tuberculosis infections. These antibiotic-resistant bacteria survive and pass on the genes to their offspring, making the resistant phenotype more common in the population.
DNA analysis indicates that the genes for antibiotic resistance are not normally present in bacterial chromosomal DNA.
Which of the following statements best explains how the genes for antibiotic resistance can be transmitted between bacteria without the exchange of bacterial chromosomal
DNA?
The antibiotic-resistant bacteria release a hormone that signals neighboring bacteria to become resistant.
The genes for antibiotic resistance are located on a plasmid that can be passed to neighboring bacteria.
The antibiotic-resistant bacteria are the result of bacteria that specifically modify their own chromosomal DNA
DNA to neutralize the antibiotics.
The antibiotic alters the bacterial genome of each bacterium, which results in an antibiotic-resistant population.
Directions: Each group of questions below concerns an experimental or laboratory situation or data. In each case, first study the description of the situation or data. Then choose the one best answer to each question following it.
. . . glutamine-glutamine-glutamine . . .
. . . serine-serine-serine . . .
Which of the following messenger RNA sequences could code for both of the two amino acid sequences above, simply by a shift in the reading frame?
. . . AGCAGCAGCAGC . . .
. . . AGUAGUAGUAGU . . .
. . . CAACAACAACAA . . .
. . .GCUGCUGCUGCU . . .
. . . GCAAGCGCAAGC . . .
The lac operon in E. coli consists of genes that code for enzymes necessary for the breakdown of lactose. When lactose is absent, the operon is inactive because a repressor protein binds to a specific site in the lac operon. When lactose is present, lactose molecules bind to the repressor protein, causing the repressor protein to dissociate from the binding site. In the absence of glucose (a preferred energy source for bacteria), the protein CAP binds to a regulatory site near the lac promoter to activate transcription of the lac operon.
The following symbols represent the macromolecules involved in regulation of the lac operon. see image
In the diagrams below, the horizontal line represents the lac operon and the bent arrow represents the transcription start site of the lacoperon. Which of the following diagrams best represents the scenario in which lactose is available to the cell and glucose is absent?
The p53 protein regulates a cellular response to DNA damage. Based on the diagram above, which of the following best describes the role of p53 in the response to DNA damage?
Phosphorylated p53 binds to DNA and repairs the damage.
Phosphorylated stimulates transcription of , and the resulting protein suppresses cell division until the damage is repaired.
Phosphorylated binds complexes, and the resulting protein complex repairs the damage.
Phosphorylated activates proteins, and the proteins in turn repair the damage.
The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mostly of individuals with pronounced pelvic spines, as shown in Figure 1. Individuals in freshwater stickleback populations, on the other hand, typically have reduced pelvic spines, as shown in Figure 2.
As represented in Figure 1 and Figure 2, the phenotypic difference between marine and freshwater sticklebacks involves Pitx1, a gene that influences the formation of the jaw, pituitary gland, and pelvic spine. Enhancer sequences upstream of the Pitx1 genetic locus regulate expression of the Pitx1 gene at the appropriate times and in the appropriate tissues during development. Previous studies have found that a mutation in the hindlimb enhancer interferes with the formation of a pronounced pelvic spine.
A mutation that affects Pitx1 gene function in all tissue types is most likely to be at which of the following genetic loci?
Hindlimb enhancer
Pituitary enhancer
Jaw enhancer
Promoter
Cells that contain only circular chromosomes are most probably which of the following?
Protist cells
Fungal cells
Bacterial cells
Plant cells
Animal cells
Which of the following best describes a characteristic of that makes it useful as hereditary material?
There are many different types of nucleotide bases that can be incorporated into DNA.
The nucleotide bases can also be used to provide the energy needed for reproduction.
Nucleotide bases can be randomly replaced with different nucleotide bases to increase variation.
Nucleotide bases in one strand can only be paired with specific bases in the other strand.
Antigens are foreign proteins that invade the systems of organisms. Vaccines function by stimulating an organism’s immune system to develop antibodies against a particular antigen. Developing a vaccine involves producing an antigen that can be introduced into the organism being vaccinated and which will trigger an immune response without causing the disease associated with the antigen. Certain strains of bacteria can be used to produce antigens used in vaccines.
Which of the following best explains how bacteria can be genetically engineered to produce a desired antigen?
The gene coding for the antigen can be inserted into plasmids that can be used to transform the bacteria.
The bacteria need to be exposed to the antigen so they can produce the antibodies.
The of the antigen has to be transcribed in order for the produced to be inserted into the bacteria.
The of the antigen has to be translated in order for the protein to be inserted into the bacteria.
Oncogenes are genes that can cause tumor formation as a result of a particular mutation. Which of the following potential therapies would be most effective at preventing the expression of an oncogene?
Reducing the number of ribosomes in the cell to prevent the creation of the oncogene’s proteins
Blocking membrane-bound receptors of transcription factors
Introducing a chemical that binds to transcription factors associated with the oncogene’s promoter
Producing additional transcription factors for tumor suppressor genes in the cell
Which of the following best explains how some cells of an individual produce and secrete a specific enzyme, but other cells of the same individual do not?
The cells contain different genes and therefore do not make the same proteins.
The cells have evolved under different selective pressures, resulting in some cells making proteins that others cannot.
The cells transcribe and translate different combinations of genes, leading to the production of different sets of proteins.
The cells produce different types of ribosomes that enable the translation of different genes.
Sickle-cell anemia is associated with a mutation in the gene encoding the beta subunit of hemoglobin that results in a change from glutamic acid to valine at position 6. All other amino acids are identical to a normal hemoglobin molecule.
Based on the information above, which of the following mutations is the most likely cause of sickle-cell anemia?
A single base-pair substitution in the gene encoding the beta subunit
A single base-pair insertion in the gene encoding the beta subunit
A single base-pair deletion in the gene encoding the beta subunit
A translocation of DNA from one chromosome to another
Which of the following correctly explains the process shown in Figure 1 ?
DNA replication is occurring because replication is semi-conservative and the new strand is a copy of the template strand.
Initiation of transcription is occurring because a strand of RNA
is being produced from a DNA template strand.
Translation is occurring because the two strands have separated and a new strand is being produced.
Alternative splicing of mRNA is occurring because the mRNA
strand is being synthesized from only one strand of DNA
.
