AP Bio Test Questions
Which of the following best describes how sticklebacks in the same population with identical copies of the Pitx1 gene can still show phenotypic variation in the pelvic spine character?
Expression of the Pitx1 gene is affected by mutations at other genetic loci
Which of the following correctly illustrates a dipeptide and an amino acid in the optimal position to form a tripeptide?
****come back**** images he uploaded only had one amino acid option- so look for an OH and double bounded O group and an amino (N) group
Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?
12%
How many base pairs is the DNA fragment circled in red below? (this is on the quiz we took)
3,750bp
Which of the following help(s) to stabilize mRNA by inhibiting its degradation and protects mRNA as it leaves and travels outside the nucleus?
5' G cap and poly-A tail
During translation, the ___ site brings in the next amino acid to be added to the chain while the ___ site within the ribosome hold the growing polypeptide chain. The ___ site of the ribosome is where a tRNA that has had its amino acid removed will exit the ribosome during protein synthesis. Which answer has the corresponding sites of the ribosome listed out in the order they would appear above?
A, P, E
The processes illustrated in the models above all result in which of the following? (Can't find the exact image, but it contains pictures of crossing over, conjugation ((bacterial 'fertilization')), and fertilization)
An increase in genetic diversity
Which enzyme catalyzes the elongation of a DNA strand in the 5' to 3' direction?
DNA polymerase III
Which of the following unwinds and unzips the DNA strands during replication?
Helicase
The Trp operon is coordinately regulated group of genes that are required for tryptophan biosynthesis in E. coli bacteria. Based on the figure above, which of the following correctly describes the regulation of tryptophan?
In the presence of tryptophan, the repressor is active and binds to the trp operator, preventing RNA polymerase from transcribing the operon.
The segment of DNA shown in Figure 20.2 has restriction sites I and II, which create restriction fragments A, B, and C when exposed to restriction enzymes. Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?
It should look like fragment C followed with a lot of space and then fragments A and B
There is a plasmid with restriction sites for BamHI and EcoRI. Several restriction digests were done using these two enzymes either alone or in combination. Hint: Begin by determining the number and size of the fragments produced with each enzyme. Which lane shows the fragments produced when the plasmid was incubated with both EcoRI and BamHI?
Lane IV
Mutations in DNA are usually caused by chemical or radiation damage to DNA molecules, followed by imperfect repair of the damage. Immediately after this kind of imperfect repair, there may be a mismatched base pair in the DNA. The illustration below shows an example of a mismatch, with the relevant pair bases in bold. Which of the following best represents the DNA of the two daughter cells produced when a bacterial cell with this particular mismatch replicated its DNA and divides?
Mutant in one but not the other
The pedigree suggests that the gene is on a nuclear chromosome, and not on mitochondrial DNA, because
Maternal mitochondrial mutations are inherited by all of a mother's offspring
Based on a universal genetic code, which of the following represents the correct polypeptide that will result from the translation of the mRNA molecule shown, beginning with the first available start codon?
Met-Val-Thr-Lys-Phe-Gly-His
In his transformation experiments, what did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form
Comparison of DNA sequences in Table II suggests that a functional GULO gene in lemurs can have a G, C, or T at position 21, but only a G at position 22. Which of the following pairs of predictions is most helpful in explaining the discrepancy?
No change to the protein; A premature stop codon or an amino acid with different biochemical characteristics
Based on the experiment above, which of the following best explains why there are fewer colonies on plate IV (E. Coli with resistance plasmid and has ampicillin) than on plate III (Wild type E. Coli with no ampicillin)?
Not all E. Coli cells are successfully transformed with the ampicillin resistant gene
The sequences of two short fragments of DNA are shown above. Which of the following is one way in which the two segments would differ? (picture has two segments of DNA with segment one having mostly A's and T's and segment two having mostly C's and G's)
Segment 1 would denature faster during PCR heating than segment two (A's and T's have two hydrogen bonds while C's and G's have three)
In a transformation experiment, E. coli bacteria was mixed with plasmid containing the gene for resistance to the antibiotic ampicillin. Plasmid was not added to a second sample. Samples were plated on nutrient agar plate, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria. Plates that have only ampicillin-resistant bacteria growing include which of the following?
Should be the dish with dots in it that has the presence of ampicillin (due to the fact all nonresistant bacteria was killed)
What is meant by the description "antiparallel" regarding the strands that make up DNA?
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
Retroviruses have an RNA genome. HTLV-1 is a lysogenic retrovirus that establishes a latent infection in human cells. By which of the following mechanisms does infection by a retrovirus such as HTLV-1 most likely cause long-lasting genetic changes to host cells?
The RNA viral genome has to be reverse transcribed into DNA and then they can integrate into the host genome
Which of the following is the most likely effect of the mutation at position 7 in the GULO gene of humans?
The deletion of a single nucleotide causes a frame shift, changing the primary structure downstream of the mutation and resulting in a nonfunctional protein
Based on the experiment above, which of the following best explains why there is no growth on plate II (E. coli with no resistance plasmid with ampicillin)
The initial E. coli culture was not ampicillin-reistant
In sticklebacks, which of the following is most likely to occur if the jaw enhancer is disabled instead of the hindlimb enhancer?
The jaw does not develop normally, but a pronounced pelvic spine does develop because the Pitx1 gene is expressed in the developing pelvis but not in the developing jaw
The cells lining the respiratory tract of pigs have receptors for both avian and human influenza virus. Based on the model above, which of the following best describes the origin of the new strain of human influenza virus?
The new viral strain inherited a combination of genetic material from both avian influenza and human influenza virus
Why are viruses referred to as obligate parasites?
They cannot reproduce outside of a host cell
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 (an amino acid) to valine (another amino acid) at position #6. All other amino acids are identical to another hemoglobin protein. 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 thr beta subunit
Which of these mutations would be most likely to have a harmful effect on an organism?
a single nucleotide insertion downstream of, and close to, the start codon
Muscle cells differ from nerve cells mainly because they
express different genes
In 1997, Dolly the sheep was cloned. Which of the following processes was used?
fusion of an adult cell's nucleus with a de-nucleated sheep egg, followed by incubation in a surrogate female
When DNA replicates, each strand of the original DNA molecule is used as a template for the synthesis of a second, complementary strand. Which of the following figures most accurately illustrates enzyme-mediated synthesis of new DNA at a replication fork?
one arrow pointing in the direction of 3' and helicase, three arrows pointing in the direction of 5' and away from helicase
Testosterone is an example of a hormone that can act as a factor involved in the production of proteins. Which picture below best represents how testosterone can alter gene expression of these proteins?
picture with a steroid hormone, receptor molecule, hormone receptor complex, transcription, and translation
A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (MRNA). The following transfer RNA molecules are available. Two of them can correctly match the mRNA so that a dipeptide can form. The dipeptide that will form will be
proline-theronine
The TATA sequence is found only several nucleotides away from the start site of transcription. This most probably relates to which of the following?
the physical spacing necessary for RNA polymerase and transcriptions factors to bind the DNA
Lactose digestion in E.coli begins with its hydrolysis by the enzyme B-galactosidase. The gene encoding B-galacrosidase, lacZ, is part of a coordinately regulated operon containing other genes required for lactose utilization. Which of the following figures correctly depicts the interactions at the lac operon when lactose is NOT present or being utilized?
there is a repressor protein attached to the operon and there is no lactose present in the picture ( Remember Slack Off- the lac operon is naturally turned off and the presence of lactose is required to detach it)