5 Written questions
5 Matching questions
- In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a
B) replication and dedifferentiation of adult stem cells from sheep bone marrow
C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
D) isolation of stem cells from a lamb embryo and production of a zygote equivalent
E) use of mitochondrial DNA from adult female cells of another ewe
- In large scale, genome-wide association studies in humans, correlation is sought between
A) large inversions that displace the centromere.
B) lengthy sequences that might be shared by most members of a population.
C) single nucleotide polymorphisms in two or more adjacent genes.
D) single nucleotide polymorphisms found only in persons with a particular disorder.
E) single nucleotide polymorphisms found in families with a particular introns sequence.
- Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis?
B) hepatitis virus
- Which of the following represents a difference between viruses and viroids?
A) Viruses have capsids composed of protein, whereas viroids have no capsids.
B) Viruses cannot pass through plasmodesmata, whereas viroids can.
C) Viruses contain introns, whereas viroids have only exons.
D) Viruses infect many types of cells, whereas viroids infect only prokaryotic cells.
E) Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA.
- A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. She tried decreasing the amount of methylation enzymes in the embryonic stem cells and then allowed the cells to further differentiate. Which of the following results would she most likely see?
A) increased chromatin condensation
B) decreased chromatin condensation
C) inactivation of the selected genes D) decreased binding of transcription factors
E) abnormalities of mouse embryos
- a A) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
- b D) single nucleotide polymorphisms found only in persons with a particular disorder
- c E) abnormalities of mouse embryos
- d D) rabies
- e A) viruses have capsids composed of protein, whereas viroids have no capsids
5 Multiple choice questions
- D) A retrovirus is used to introduce four specific regulatory genes
- B) methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication
- C) include a transgenic rice plant that can help prevent vitamin A deficiency
- E) retroviruses
- D) Dicer enzyme has reduced it to smaller double-stranded pieces
5 True/False questions
When DNA is compacted by histones into 10-nm and 30-nm fibers, the DNA is unable to interact with proteins required for gene expression. Therefore, to allow for these proteins to act, the chromatin must constantly alter its structure. Which processes contribute to this dynamic activity?
A) DNA supercoiling at or around H1 B) hydrolysis of DNA molecules where they are wrapped around the nucleosome core
C) accessibility of heterochromatin to phosphorylating enzymes
D) nucleotide excision and reconstruction
E) methylation and phosphorylation of histone tails → C) by adding methyl groups to adenines and cytosines
Pharmacogenetics is an increasingly important discipline that uses genetic information to tailor the prescription of drug treatments to individuals. In the case of chemotherapy for breast cancer, for example, different patients need and/or respond to different treatments.
Breast tumor biopsy specimens can be typed for a number of gene expression patterns. Together, these can provide risk analysis for the likely aggressive growth and metastasis of the tumor. How can this most help the physician and patient?
A) This can help them decide whether the tumor should be removed.
B) Some patients want to know as much as possible.
C) This can help to aggregate health statistics.
D) Some physicians may use the information to decide what to do, but not tell the patient.
E) This can help them to decide whether and what kind of chemotherapy is warranted. → E) This can help them to decide whether and what kind of chemotherapy is warranted
A eukaryotic gene has "sticky ends" produced by the restriction endonucleaseEcoRI. The gene is added to a mixture containingEcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
Bacteria that do not take up any plasmids would grow on which media?
A) the nutrient broth and the tetracycline broth
B) all three broths
C) the tetracycline broth and the ampicillin broth
D) the nutrient broth and the ampicillin broth
E) the nutrient broth only → D) the anterior- posterior axis
Which of the following is an example of post-transcriptional control of gene expression?
A) the folding of DNA to form heterochromatin
B) the binding of transcription factors to a promoter
C) the removal of introns and alternative splicing of exons
D) the addition of methyl groups to cytosine bases of DNA
E) gene amplification contributing to cancer → B) Transferred genes may not have appropriately controlled activity
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments she succeeded in decreasing methylation of histone tails. Which of the following results would she most likely see?
A) inactivation of the selected genes B) increased chromatin condensation
C) abnormalities of mouse embryos D) decreased chromatin condensation
E) decreased binding of transcription factors → B) increased chromatin condensation