Which of the following best predicts the effects of a mutation in the promoter of the TYR gene

AP Bio Unit 6

Scientists conducted a transformation experiment using E. coli bacteria and the pTru plasmid. Samples of the pTru plasmid (lane A) and the chromosomal DNA from two different E. coli strains that the scientists attempted to transform (lane B and lane C) we

E. coli in lane C have been successfully transformed and contain additional genetic information.

Which of the following best explains how the pattern of DNA arrangement in chromosomes could be used, in most cases, to determine if an organism was a prokaryote or a eukaryote?

prokaryotes have DNA arranged in a single circular chromosome and eukaryotes have DNAarranged in multiple linear chromosomes.

Lynch syndrome is an inherited condition associated with an increased risk for colon cancer, as well as certain other cancers. Mutations in one of several genes involved in DNA repair during DNAreplication have been associated with Lynch syndrome. DNA seq

The individual has an increased risk of developing colon cancer.

An evolutionary biologist hypothesizes that two morphologically similar plant species are not closely related. To test the hypothesis, the biologist collects DNA samples from each of the two plant species and then uses restriction enzymes to cut the DNA s

Species B has more short fragments of DNA than species A does.

Labeled nucleotides were supplied to a cell culture before the cells began DNA replication. A simplified representation of the process for a short segment of DNA is shown in Figure 1. Labeled DNA bases are indicated with an asterisk (*).
Figure 1. A simpl

Each newly synthesized strand remains associated with its template strand to form two copies of the original DNA molecule.

Cycloheximide (CHX) is a eukaryote protein synthesis inhibitor. It is used in biomedical research to inhibit protein synthesis in eukaryotic cells studied in vitro. Its effects are rapidly reversed by simply removing it from the culture medium.
In a trans

In the presence of the drug, protein synthesis halted and the polypeptide chain stopped growing. When the drug was removed, however, elongation resumed and the polypeptide chain started growing again

Retroviruses such as HIV and hepatitis B virus use RNA as their genetic material rather than DNA. In addition, they contain molecules of reverse transcriptase, an enzyme that uses an RNA template to synthesize complementary DNA.
Which of the following bes

The reverse transcriptase will produce DNA from the viral RNA, which can be incorporated into the host's genome and then transcribed and translated.

Exposure to ultraviolet (UV) radiation is the leading cause of skin cancer in humans. Figure 1 shows a model of how UV exposure damages DNA.
Figure 1. Model of damage to DNA caused by UV exposure
Which of the following statements best explains what is sho

UV photons cause dimers to form, leading to misshapen DNA, which results in replication and transcription errors.

The trp operon in E. coli is an example of a repressible operon that consists of genes coding for enzymes used to synthesize tryptophan. When tryptophan levels are high, the operon is turned off and these genes are not transcribed. However, it is also kno

When trpR is mutated, the trp operon is transcribed regardless of tryptophan levels.

ukaryotes transcribe RNA from DNA that contains introns and exons. Alternative splicing is one posttranscriptional modification that can create distinct mature mRNA molecules that lead to the production of different proteins from the same gene. Figure 1 s

The cell will die because it is unable to metabolize the substrate without enzyme A, which is structurally specific for the substrate shown.

A simplified model of a DNA replication fork is represented in Figure 1. The protein labeled Enzyme 1 carries out a specific role in the DNA replication process.
Figure 1. A simplified model of a DNA replication fork
Which of the following statements best

Enzyme 1 is a topoisomerase that relieves tension in the overwound DNA in front of a replication fork.

Which of the following claims about the TYR, TRP2, and TRP1 mammalian genes is most likely to be accurate?

The TYR, TRP2, and TRP1 genes may be located on different chromosomes but are activated by the same transcription factor.

Which of the following claims best explains why keratinocytes do not produce melanin?

Keratinocytes do not express the MITF gene.

Mice have melanocytes in the skin on their ears and show a tanning response to UV radiation. Researchers were studying a mutant population of mice that do not show a tanning response. Genetic testing of these mutant mice showed that the pathway causing th

When researchers applied a drug that activates adenylyl cyclase to the mutant mice's ears, the level of melanin increased.

Based on the information provided in Figure 1 and Figure 2, which of the following best predicts the effects of a mutation in the promoter of the TYR gene that prevents it from being transcribed?

Skin pigmentation will not be able to change, resulting in a negative selection pressure.

Which of the following best explains a process occurring between point 1 and point 2 in Figure 3 ?

A poly?A tail is added to RNA.

Researchers discovered a mutant form of the TYR gene with a deletion of a single guanine nucleotide in the beginning of the coding sequence.
Which of the following best predicts the phenotype of an individual who is homozygous for this TYR mutation?

The mutation will change all subsequent amino acids in the TYR protein, leading to nonfunctional TYR protein. Individuals with this mutation will lack melanin in their hair, skin, and eyes and will not tan in response to UV radiation.

Small single-stranded RNA molecules called microRNAs (miRNAs) are capable of base pairing with specific binding sites in the 3? untranslated region of many mRNA transcripts. Transcription of gene Q yields an mRNA transcript that contains such an miRNA bin

When the miRNA binding site sequence is altered, translation of Q mRNAoccurs in the presence of miRNA-delta.

All cells must transcribe rRNA in order to construct a functioning ribosome. Scientists have isolated and identified rRNA genes that contribute to ribosomal structure for both prokaryotes and eukaryotes. Figure 1 compares the transcription and processing

Sections of the pre-rRNA are removed, and the mature rRNA molecules are available to combine with proteins to form the ribosomal subunits.

Huntington's disease, an autosomal dominant disorder, is caused by a mutation in the HTT gene. The HTT gene contains multiple repeats of the nucleotide sequence CAG. A person with fewer than 35 CAG repeats in the HTT gene is unlikely to show the neurologi

She inherited an allele with more than 40 CAG repeats in the HTT gene from her father.

Figure 1 depicts a simplified model of a replication bubble.
Figure 1. DNA replication bubble.
Which of the following best explains how this model illustrates DNA replication of both strands as a replication fork moves?

I is synthesized continuously in the 5? to 3? direction, and III is synthesized in segments in the 5? to 3? direction.

Figure 1 represents a portion of a process that occurs during protein synthesis.
Figure 1. Model of selected features of DNA transcription
Which claim is most consistent with the information provided by the diagram and current scientific understanding of

Some sequences of DNA can interact with regulatory proteins that control transcription.

Cystic fibrosis (CF) is a progressive genetic disease that causes persistent lung infections and affects the ability to breathe. CF is inherited in an autosomal recessive manner, caused by the presence of mutations in both copies of the gene for the cysti

Deletion, because a thymine is missing, which changes the reading frame.

Nucleotide base pairing in DNA is universal across organisms. Each pair (T?A; C?G)consists of a purine and a pyrimidine. Which of the following best explains how the base pairs form?

Hydrogen bonds join a double-ringed structure to a single-ringed structure in each pair.

Which of the following claims about the Tyr TRP2 and TRP1 mammalian genes is most likely to be accurate quizlet?

Are Tyr TRP2 and TRP1 on the same chromosome?

Which of the following best predicts what will happen when a normal cell is exposed to a retrovirus?

Which of the following best supports the claim that binding of miRNA Delta to the miRNA binding site inhibits translation of gene Q?