Unit V Lecture Exam

What is difference between an epidemic and a pandemic?

An epidemic is restricted to a local region; a pandemic is global.

Figure 20.6

Be able to have an understanding about the restrictive enzymes

What are the differences of cloning and gene cloning?

Cloning:is the production of identical copies of DNA Gene Cloning:is production of many identical copies of the same gene.

A sequence database such as GenBank could be used to do all of the following EXCEPT

Compare patterns of gene expression in cancerous and non-cancerous cells.

Which of the following tools of recombinant DNA technology is incorrectly paired with its use?

DNA ligase—cutting DNA, creating sticky ends of restriction fragments

What was the goal behind the Human Genome Project? When was it completed?

Human Genome Project goal was designed to provide information that other researchers can use to link genetic variants to the risk for specific illnesses, which will lead to new methods of preventing, diagnosing, and treating disease. Started in 1990 and was completed in 2000.

What is the main structural difference between enveloped and nonenveloped viruses?

Enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane

What is the purpose of restrictive enzymes? What purpose does DNA ligase serve for genetic engineering

Restrictive enzymes: bacterial enzyme that cuts DNA, it creates fragments of DNA with "sticky ends" DNA ligase: joins DNA fragments together

What are the three types of transgenic organisms? What are some ways in which these transgenic organisms can be used?

Transgenic Bacteria: Insulin, Clean up oil, Growth hormone Transgenic Animal: Pharmaceutical inserted into milk Transgenic Plant: Toxins in plants to keep insect from consuming the plant

Evidence suggests that factors which contribute towards the virulence of E. coli strain O157:H7, a bacterial strain reported to cause several food poisoning deaths, are caused by genes from a virus that infects bacteria. Considering this evidence, which statement most likely explains how the O157:H7 population acquired the genetic variation that distinguishes the strain from harmless E. coli strains, such as those that reside in our intestines?

The virus infected the bacterium, and allowed the bacterial population to replicate with a copy of the phage genome in each new bacterium.

Which of the following is true of embryonic stem cells but not of adult stem cells?

They can give rise to all cell types in the organism.

Explain the five steps to a lytic viral infection

Use Figure 19.5 (This figure shows and explains all five steps)

Which of the following is one of the technical reasons why gene therapy is problematic?

Transferred genes may not have appropriately controlled activity.

When gene duplication occurs to its ultimate extent by doubling all genes in a genome, what has occurred?

creation of a polyploid

If the sequence of a cDNA has matches with DNA sequences in the genome, then this genomic DNA is likely to _____.

code for a protein

Imagine that you compare two DNA sequences found in the same location on homologous chromosomes. On one of the homologs, the sequence is AACTACGA. On the other homolog, the sequence is AACTTCGA. Within a population, you discover that each of these sequences is common. These sequences _____.

contain an SNP that may be useful for genetic mapping

Bacterial cells protect their own DNA from restriction enzymes (endonucleases) by _____.

adding methyl groups to adenines and cytosines

A DNA microarray is a tool that owes its existence to earlier genomics investigations. What essential contribution of genomics makes microarrays possible?

knowledge of which DNA sequences to synthesize for the arra

In 1997, Dolly the sheep was cloned. Which of the following processes was used?

fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate

A multigene family is composed of _____

genes whose sequences are very similar and that probably arose by duplication

Genetically engineered plants _____.

include transgenic rice plants that can grow in water of high salinity

Effective antiviral drugs are usually associated with which of the following properties?

interference with viral replication

Gene Therapy

involves procedures to give patients healthy genes to make up for a faulty gene

Plasmids

is a small accessory ring of DNA in the cytoplasm of some bacteria

In the form of gene therapy used successfully for severe combined immunodeficiency syndrome (SCID)-X1, the genetic engineering of human cells is done by _____.

isolating the patient's bone marrow cells, infecting them with genetically engineered viruses, and injecting them back into the patient's bone marrow

Many identical copies of genes cloned in bacteria are produced as a result of _____.

plasmid and bacterial cell replication

A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing?

polymerase chain reaction (PCR)

One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome?

prevention of transmission of plant allergens to the vaccine recipients

What is metagenomics?

sequencing DNA from a group of species from the same ecosystem

Homeobox

similar genes that direct the formation of many body structures during early embryonic development

Exon shuffling occurs during _____.

meiotic recombination

The virus genome and viral proteins are assembled into virions (virus particles) during _____

the lytic cycle only

The host range of a virus is determined by _____.

the proteins on its surface and that of the host

Although transposable elements and short tandem repeats (STRs) are repetitive DNAs, they differ in that _____.

the repeated unit in STRs is clustered one after another; transposable element repeats are scattered throughout the genome

What are the steps to creating a DNA recombinant?

1. Recombinant DNA (rDNA) contains DNA from two or more different sources.2. To make rDNA, technician selects a vector.3. A vector is a plasmid or a virus used to transfer foreign genetic material into a cell.4. A plasmid is a small accessory ring of DNA in the cytoplasm of some bacteria.5. Plasmids were discovered in research on reproduction of intestinal bacteria Escherichia coli.6. Introduction of foreign DNA into vector DNA to produce rDNA requires two enzymes.  a. Restriction enzyme is a bacterial enzyme that cuts DNA, it creates fragments of DNA with "sticky ends" b. DNA ligase joins fragments together

Current analysis indicates that less than 2% of the human genome codes for proteins. Based on the systems approach employed by the ENCODE project, what percentage of the genome is estimated to contain functional elements (includes functional RNAs and regulatory sequences)?

At least 80%

What is DNA Fingerprinting? How come forensic scientists can use to identify individuals?

DNA Fingerprinting: is the technique of using DNA fragment lengths, resulting from restriction enzyme cleavage and amplified by PCR, to identify particular individuals. DNA fingerprinting can identify deceased individuals or perpetrators of crimes

Why do scientists consider HIV to be an emerging virus?

HIV suddenly became apparent and widespread in the 1980s.

Which of the following processes within viral replication is the greatest source of genetic variation in RNA virus populations?

High mutation rate due to lack of proofreading of RNA genome replication errors

The final step in a Sanger DNA sequencing reaction is to run the DNA fragments on a gel. What purpose does this serve?

It separates DNA fragments generated during the sequencing reaction based on one-nucleotide differences in their size.

Be able to read a Gel Electrophoresis -- Who done it?

Look at your notes

Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is also found in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following?

Pax-6 is highly conserved and shows shared evolutionary ancestry.

What is a polyploidy? Which organisms is it more common in finding this type of condition? Why would it be a benefit to humans to have this organism to be a polyploidy?

Polyploidy: Have an extra set of chromosomes Plants are more likely to be ployploidy because animals do not survive. Humans benefit from having polyploidy plants by having more food. (examples of polyploidy plants are: Strawberries, wheat, citrus food)

In 2009, a flu pandemic was believed to have originated when viral transmission occurred from pig to human, thereby earning the designation, "swine flu." Although pigs are thought to have been the breeding ground for the 2009 virus, sequences from bird, pig, and human viruses were all found within this newly identified virus. What is the most likely explanation of why this virus contained sequences from bird, pig, and human viruses?

Related viruses can undergo genetic recombination if the RNA genomes mix and match during viral assembly.

Humans have twenty-three pairs of chromosomes and chimps have twenty-four pairs of chromosomes. What is the most likely explanation for these differences in human and chimp genomes?

The common ancestor of humans and chimps had twenty-four pairs of chromosomes. After the two groups evolved, two human chromosomes fused end to end

Use the following information to answer the question(s) below. The herpes viruses are important enveloped DNA viruses that cause disease in vertebrates and in some invertebrates such as oysters. Some of the human forms are herpes simplex virus (HSV) types I and II, causing facial and genital lesions, and the varicella zoster virus (VSV), causing chicken pox and shingles. Each of these three actively infects nervous tissue. Primary infections are fairly mild, but the virus is not then cleared from the host; rather, viral genomes are maintained in cells in a latent phase. The virus can later reactivate, replicate again, and infect others. In electron micrographs of HSV infection, it can be seen that the intact virus initially reacts with cell surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsids go from being full to being "empty." Which of the following best fits these observations?

The viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane, and the genome is all that enters the nucleus.

What is an advantage of the whole-genome shotgun sequencing approach, compared to the ordered process used by the International Human Genome Consortium?

The whole-genome shotgun approach is much faster

In animals, what is the difference between reproductive cloning and therapeutic cloning?

Therapeutic cloning supplies cells for repair of diseased or injured organs.

Unequal crossing over during prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of hemoglobin, so-called hemoglobin Lepore, exists in the human population. Hemoglobin Lepore has a deleted series of amino acids. If this mutated form was caused by unequal crossing over, what would be an expected consequence?

There should also be persons whose hemoglobin contains two copies of the series of amino acids that is deleted in hemoglobin Lepore.

Figure 19.4

There will be two questions looking at this diagram

What is the purpose to a vector?

Transfer foreign genetic material into a cell

What are transposable elements? Who was the scientist that determined the transposable elements? What organism did she study to see this in action?

Transposable Elements: Stretches of DNA that can move locations Barbara McClintock Indian Corn

In what ways is a virus like an organism? How is it different

Viruses are like a living organism because they can reproduce but can not reproduce without a host cell. Viruses and living organisms also contain genetic material.

A recent study compared the Homo sapiens genome with that of Neanderthals. The results of the study indicated that there was a mixing of the two genomes at some period in evolutionary history. Additional data consistent with this hypothesis could be the discovery of _____.

a few modern H. sapiens with some Neanderthal sequences

Which of the following problems with animal cloning might result in premature death of the clones?

abnormal gene regulation due to variant methylation

Yeast cells are frequently used as hosts for cloning because they _____.

are eukaryotic cells

Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. These can now be used to _____.

better understand the evolutionary relationships among members of related taxa

The first class of drugs developed to treat AIDS, such as AZT, were known as reverse transcriptase inhibitors. They worked because they _____.

bonded to the viral reverse transcriptase enzyme, thus preventing the virus from making a DNA copy of its RNA genome

Biologists now routinely test for homology between genes in different species. If genes are determined to be homologous, it means that they are related _____.

by descent from a common ancestor

Transgenic mice are useful to human researchers because they _____.

can be valuable animal models of human disease

Which of the following accounts for someone who has had regular herpesvirus-mediated cold sore or genital sore flare-ups?

copies of the herpesvirus genome permanently maintained in host nuclei

Preparing a physical map of the genome involves _____.

cutting the DNA of each chromosome into restriction fragments that overlap, and then determining the original order of the fragments

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. We expect that the plants would _____.

develop the typical symptoms of TMV infection

Refer to the treatments listed below to answer the following question(s). You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at your disposal to analyze the substance and determine the nature of the infectious agent. I. Treat the substance with enzymes that destroy all nucleic acids and then determine whether the substance is still infectious. II. Filter the substance to remove all elements smaller than what can be easily seen under a light microscope. III. Culture the substance on nutritive medium, away from any plant cells. IV. Treat the sample with proteases that digest all proteins and then determining whether the substance is still infectious. If you already know that the infectious agent was either a viroid or a prion, which method(s) listed above would allow you to distinguish between these two possibilities?

either I or IV

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for that domain of a protein that binds to DNA in a regulatory developmental process. Therefore, you would expect that _____.

homeotic genes are selectively expressed as an organism develops

After finding a new medicinal plant, a pharmaceutical company decides to determine if the plant has genes similar to those of other known medicinal plants. To do this, the company annotates the genome of the new plant to _____.

identify genes and determine their functions

The reason for using Taq polymerase for PCR is that _____

it is heat stable and can withstand the heating step of PCR

Gene therapy requires _____.

knowledge and availability of the normal allele of the defective gene, an ability to introduce the normal allele into the patient, and an ability to express the introduced gene at the correct level, and time, and tissue site within the patient

What are prions?

misfolded versions of normal protein that can cause disease

To make a vaccine against mumps, measles, or rabies, which type of viruses would be useful?

negative-sense ssRNA viruses

A virus consisting of a single strand of RNA, which is transcribed into complementary DNA, is a _____

retrovirus

A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using _____.

reverse transcriptase to reconstruct the gene from its mRNA

A population of viruses with similar characteristics is called a _____.

strain

Proteomics is defined as the _____.

study of the full protein set encoded by a genome

In recombinant DNA methods, the term vector can refer to

the enzyme that cuts DNA into restriction fragments.

Some viruses can be crystallized and their structures analyzed. One such virus is yellow mottle virus, which infects beans. This virus has a single-stranded RNA genome containing about 6300 nucleotides. Its capsid is 25-30 nm in diameter and contains 180 identical capsomeres. If the yellow mottle virus begins its infection of a cell by using its genome as mRNA, which of the following would you expect to be able to measure?

translation rate

Polymerase Chain Reaction (PCR)

uses the enzyme DNA polymerase to carry out multiple replications (a chain reaction) of target DNA.