AP Bio
(Look at handout) Which of the following best explains a process eccuring between point 1 and pint 2 in Figure 1?
A poly-A tail is added to RNA
Which of the following would you expect of a eukaryote lacking telomerase?
A reduction in chromosome length inn gametes.
Which enzyme synthesizes tRNA?
Aminoacyl-tRNA synthease
Transfer RNA _______
Binds to it's specific amino acid in the active site of an aminoacyl-tRNA synthesis
Alternative RNA splicing ______
Can allow the production of proteins of different sixes and functions from a single mRNA
DNA contains the template needed to copy itself, but it has no catalytic activity in cells. What catalyzes the formation of phosphodiester bonds between adjacent nucleotides in the DNA polymer being formed?
DNA Polymerase
Which of the following correctly explains where DNA replication will begin on the strand oriented 5'-3' reading from left to right?
DNA replication will be initiated immediately to the left of the RNA since DNA polymerase requires an RNA primer
Which of the following correctly explains where DNA replication will begin on the strand oriented 5'-3', reading from left to right?
DNA replication will be initiated immediately to the left of the RNA, since DNA polymerase requires an RNA primer.
Based on the information in Figure 1 which type of mutation explains the nature of the change in DNA that resulted in cystic fibrosis in the affected individual?
Deletion because a thymine is missing which changes the reading frame.
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. Which of the following statements best explains the role of Enzyme 1 in the DNA replication process?
Enzyme 1 is a topoisomerase that relieves tension in the over-wound DNA in front of a replication fork.
Which of the following is not ture of a codon?
Extends from one end of a tRNA molecule
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.
(Figure 1: Process occurring in a cell) Which of the following correctly explains the process shown in Figure 1)?
Initiation of transcription is occurring because a strand of RNA is being produced from a DNA template strand.
A nonsense mutation is a gene ___________.
Intruduces a premature stop codon into mRNA.
(Look at handout) Which of the following claims best explains why keratinocytes do not produce melanin?
Keratinocytes do not express the MITF gene.
(Figure 1: Model of a process involving nucleic acids) Which of the following best explains what process is represented in Figure 1?
New DNA strands are being synthesized in the 5' to 3' direction from their DNA templates.
Which of the following statements best explains the structure and importance of plasmids to prokaryotes?
Plasmids are circular, double-stranded DNA molecules that provide genes that may aid in survival of the prokaryotic cell.
(Essay Question) 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 single cell circular chromosomes, eukaryotes have multiple linear chromosomes.
All cells must transcribe tRNA in order to construct a functional ribosome. Scientists have isolated and identified tRNA genes that contribute to ribosomal structure for both prokaryotes and eukaryotes. Figure 1 compares transcription and processing of prokaryotic and eukaryotic tRN. Which of the following statements provides the best explaination of the processes illustrated in Figure 1?
Sections of the pre-tRNA re removed, and the mature tRNA 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 3 CAG repeats in the HTT gene is unlikely to show the neurological symptoms of Huntington's disease. A person with 40 or more CAG repeats almost always becomes symptomatic. Due to errors in meiosis, an individual without symptoms of Huntington's disease can produce gametes with a larger number of CAG repeats than there are in their somatic cells. A woman developes Huntington's disease. Her father had the disorder. Her mother did not, and there is no history of the disorder in the mother's family. Which of the following best explains how the woman inherited Huntington's disease?
She inherited an allele with more than 40 CAG repeats in the HTT gene from her father.
Erwin Chargaff investigated the nucleotide composition of DNA. He analyzed DNA from various organisms and measures 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 T% are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule.
(Look at handout) Based on the information provided in Figure 1 and 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 positive selection pressure.
Antibiotics interfere with prokaryotic cell functions. Streptomycin is an antibiotic that affects the small ribosomal subunit in prokaryotes. Specifically, streptomycin interferes with the proper binding of tRNA in prokaryotic ribosomes.
Synthesis of polypeptides will be inhibited.
(Look at handout) 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 explains what strand X represents?
The antisense strand, because it is serving as a template.
(Figure 1: Cellular process involving nucleic acids) Which of the following best explains the process represented in Figure 1?
The enzyme-regulated processing pre-RNA into mature mRNA.
What is the difference between the leading strand and the lagging strand in DNA replication?
The leading strand is synthesized continuously in the 5'-3' direction, while the lagging strand is synthesized discontinuously in the 5'-3' direction.
(Look at handout) Researchers discovered a mutant form of the TYR gene with a deletion of a single guanine nucleotide in the beginning of the coding sequence.
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.
The features of this model provide evidence for which explanation of why all growing strands are synthesized in a 5' to 3' direction?
The phosphate group attached to the 5' carbon of the dTMP forms a covalent bonds with the oxygen atom attached to the 3'carbon of the growing strand.
The features of this model provide evidence for which explanation of why all growing strands are synthesized in a 5' to 3' direction?
The phosphate group, attached to the 5' carbon of the dTMP forms a covalent bond with the oxygen atom attached to the 3' carbon of the growing strand.
(Table 1: Comparison of Selected Features of Transcription and Translation) Select one:
The two processes will occur simultaneously in prokaryotes but not eukaryotes.
(Look at handout) Mice have melanocytes in the skin on their ears 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 UV radiation was fully functional. Thus, the researchers claimed that the lack of tanning response was due to a nonfunctional MC1R.
When researchers applied a drugthat activates adenylyl cylase to the mutant mice's ears, the level of melanin increased.
