18.E: Biotechnology and Genomics (Exercises)
18.1: Biotechnology
Biotechnology is the use of biological agents for technological advancement. Biotechnology was used for breeding livestock and crops long before the scientific basis of these techniques was understood. Biotechnology has grown rapidly through both academic research and private companies. The primary applications of this technology are in medicine (production of vaccines and antibiotics) and agriculture (genetic modification of crops, such as to increase yields).
Review Questions
GMOs are created by ________.
- generating genomic DNA fragments with restriction endonucleases
- introducing recombinant DNA into an organism by any means
- overexpressing proteins in E. coli.
- all of the above
- Answer
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B
Gene therapy can be used to introduce foreign DNA into cells ________.
- for molecular cloning
- by PCR
- of tissues to cure inheritable disease
- all of the above
- Answer
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C
Insulin produced by molecular cloning:
- is of pig origin
- is a recombinant protein
- is made by the human pancreas
- is recombinant DNA
- Answer
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B
Bt toxin is considered to be ________.
- a gene for modifying insect DNA
- an organic insecticide produced by bacteria
- useful for humans to fight against insects
- a recombinant protein
- Answer
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B
The Flavr Savr Tomato:
- is a variety of vine-ripened tomato in the supermarket
- was created to have better flavor and shelf-life
- does not undergo soft rot
- all of the above
- Answer
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D
Free Response
Describe the process of Southern blotting.
- Answer
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Southern blotting is the transfer of DNA that has been enzymatically cut into fragments and run on an agarose gel onto a nylon membrane. The DNA fragments that are on the nylon membrane can be denatured to make them single-stranded, and then probed with small DNA fragments that are radioactively or fluorescently labeled, to detect the presence of specific sequences. An example of the use of Southern blotting would be in analyzing the presence, absence, or variation of a disease gene in genomic DNA from a group of patients.
A researcher wants to study cancer cells from a patient with breast cancer. Is cloning the cancer cells an option?
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Cellular cloning of the breast cancer cells will establish a cell line, which can be used for further analysis
How would a scientist introduce a gene for herbicide resistance into a plant?
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By identifying an herbicide resistance gene and cloning it into a plant expression vector system, like the Ti plasmid system from Agrobacterium tumefaciens . The scientist would then introduce it into the plant cells by transformation, and select cells that have taken up and integrated the herbicide-resistance gene into the genome.
If you had a chance to get your genome sequenced, what are some questions you might be able to have answered about yourself?
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What diseases am I prone to and what precautions should I take? Am I a carrier for any disease-causing genes that may be passed on to children?
18.2: Mapping Genomes
Genome mapping is the process of finding the locations of genes on each chromosome. The maps created by genome mapping are comparable to the maps that we use to navigate streets. A genetic map is an illustration that lists genes and their location on a chromosome. Genetic maps provide the big picture and use genetic markers. A genetic marker is a gene or sequence on a chromosome that co-segregates (shows genetic linkage) with a specific trait.
Review Questions
ESTs are ________.
- generated after a cDNA library is made
- unique sequences in the genome
- useful for mapping using sequence information
- all of the above
- Answer
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D
Linkage analysis ________.
- is used to create a physical map
- is based on the natural recombination process
- requires radiation hybrid mapping
- involves breaking and re-joining of DNA artificially
- Answer
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B
Genetic recombination occurs by which process?
- independent assortment
- crossing over
- chromosome segregation
- sister chromatids
- Answer
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B
Individual genetic maps in a given species are:
- genetically similar
- genetically identical
- genetically dissimilar
- not useful in species analysis
- Answer
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A
Information obtained by microscopic analysis of stained chromosomes is used in:
- radiation hybrid mapping
- sequence mapping
- RFLP mapping
- cytogenetic mapping
- Answer
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D
Free Response
Why is so much effort being poured into genome mapping applications?
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Genome mapping has many different applications and provides comprehensive information that can be used for predictive purposes.
How could a genetic map of the human genome help find a cure for cancer?
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A human genetic map can help identify genetic markers and sequences associated with high cancer risk, which can help to screen and provide early detection of different types of cancer.
18.3: Whole-Genome Sequencing
Although there have been significant advances in the medical sciences in recent years, doctors are still confounded by some diseases, and they are using whole-genome sequencing to get to the bottom of the problem. Whole-genome sequencing is a process that determines the DNA sequence of an entire genome. Whole-genome sequencing is a brute-force approach to problem solving when there is a genetic basis at the core of a disease.
Review Questions
The chain termination method of sequencing:
- uses labeled ddNTPs
- uses only dideoxynucleotides
- uses only deoxynucleotides
- uses labeled dNTPs
- Answer
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A
Whole-genome sequencing can be used for advances in:
- the medical field
- agriculture
- biofuels
- all of the above
- Answer
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D
Sequencing an individual person’s genome
- is currently possible
- could lead to legal issues regarding discrimination and privacy
- could help make informed choices about medical treatment
- all of the above
- Answer
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D
What is the most challenging issue facing genome sequencing?
- the inability to develop fast and accurate sequencing techniques
- the ethics of using information from genomes at the individual level
- the availability and stability of DNA
- all of the above
- Answer
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B
18.4: Applying Genomics
The introduction of DNA sequencing and whole genome sequencing projects, particularly the Human Genome project, has expanded the applicability of DNA sequence information. Genomics is now being used in a wide variety of fields, such as metagenomics, pharmacogenomics, and mitochondrial genomics. The most commonly known application of genomics is to understand and find cures for diseases.
Review Questions
Genomics can be used in agriculture to:
- generate new hybrid strains
- improve disease resistance
- improve yield
- all of the above
- Answer
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D
Genomics can be used on a personal level to:
- decrease transplant rejection
- Predict genetic diseases that a person may have inherited
- Determine the risks of genetic diseases for an individual’s children
- All the above
- Answer
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A
Free Response
Explain why metagenomics is probably the most revolutionary application of genomics.
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Metagenomics is revolutionary because it replaced the practice of using pure cultures. Pure cultures were used to study individual species in the laboratory, but did not accurately represent what happens in the environment. Metagenomics studies the genomes of bacterial populations in their environmental niche.
How can genomics be used to predict disease risk and treatment options?
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Genomics can provide the unique DNA sequence of an individual, which can be used for personalized medicine and treatment options.
18.5: Genomics and Proteomics
Proteins are the final products of genes, which help perform the function encoded by the gene. Proteins are composed of amino acids and play important roles in the cell. All enzymes (except ribozymes) are proteins that act as catalysts to affect the rate of reactions. Proteins are also regulatory molecules, and some are hormones. Transport proteins, such as hemoglobin, help transport oxygen to various organs. Antibodies that defend against foreign particles are also proteins.
Review Questions
What is a biomarker?
- the color coding of different genes
- a protein that is uniquely produced in a diseased state
- a molecule in the genome or proteome
- a marker that is genetically inherited
- Answer
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B
A protein signature is:
- the path followed by a protein after it is synthesized in the nucleus
- the path followed by a protein in the cytoplasm
- a protein expressed on the cell surface
- a unique set of proteins present in a diseased state
- Answer
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D
Free Response
How has proteomics been used in cancer detection and treatment?
- Answer
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Proteomics has provided a way to detect biomarkers and protein signatures, which have been used to screen for the early detection of cancer.
What is personalized medicine?
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Personalized medicine is the use of an individual's genomic sequence to predict the risk for specific diseases. When a disease does occur, it can be used to develop a personalized treatment plan.