Fichas
Exam 3 Pt. 2
Fichas del conjunto (18)
- 1Explain how cells become differentiated or specialized into different cell types, in spite of having the same set of genes and chromosomesCertain genes are turned on and off in the process of gene regulation or gene expression.
In cellular differentiation, cells become specialized in structure and function. Different types of cells in the body look and function very differently from each other - 2Explain the role of DNA packing/X chromosome inactivationCells may use DNA packing long-term inactivation of genes.X chromosome inactivation takes place early in embryonic development of female mammals
one of the two X chromosomes in each cell is permanently inactivated at random by coiling it so tightly that transcription cannot occur. - 3Explain the role of transcription factors in control of gene expressionBinding of Transcription Factors promotes the binding of RNA polymerase to the gene, in order for transcription to occur bind to DNA and
turn the transcription of genes on and off - 4Compare where we are at with respect to the cloning of plants and animals from individual differentiated cellsThe cells of a single plant can be used to produce hundreds or thousands of identical organisms—clones from the original plant.
Nuclear transplantation involves
replacing the nucleus of an egg cell with the nucleus from a differentiated cell from an adult body The egg cell contains enzymes and factors that stimulate development,allowing the egg to develop into an adult - 5Which is more easily accomplished (Plant cloning or Animal CLonng)Plant because it's easier since all you need is a cell sample
- 6Explain what nuclear transplantation involvesreplacing the nucleus of an egg cell with the nucleus from a differentiated cell from an adult body
The egg cell contains enzymes and factors that stimulate development,
allowing the egg to develop into an adult - 7How are human embryonic stem cells obtainedThe embryos used in research have been created for reproductive purposes through in vitro fertilization procedures. When they were no longer needed for that purpose, they were donated for research by the couples who had produced them
- 8What makes embryonic stem cells such a valuable tool in medical researchresearch into development, tissue repair after injury, and new therapies for diseases that are currently untreatable
- 9What does the term Recombinant DNA meanRecombinant DNA is constructed when scientists combine pieces of DNA from two different sources to form a single DNA molecule
- 10What does it mean when we say that the “genetic code is universalAlmost all living organisms share the same genetic code, the set of rules relating nucleotide sequence in a strand of DNA/mRNA to the sequence of amino acids in the protein that it codes for.
- 11and why is this property of the genetic code absolutely essential to the usefulness of recombinant DNA technology?Because the genetic code is universal, bacteria that contain recombinant DNA plasmids can transcribe and translate the foreign gene and produce large quantities of the desired protein.
- 12What does the term GMO meangenetically modified organisms (GMO’s), organisms that have acquired one or more genes by artificial means
- 13transgenic organismA transgenic organism contains a gene from another organism, typically of another species
- 14How extensively are GMO’s currently being used in crops in the US?GM strains account for a significant percentage of several staple crops in the United States: 80% of the corn crops and 90% of the soybeans are GMO: they contain a gene from another species
- 15Explain how recombinant DNA technology is being used to produce useful products such as human insulin for medical useTo work with genes in the laboratory, biologists often use bacterial plasmids, small, circular DNA molecules that replicate separately from the larger bacterial chromosome
- 16What role do plasmids play in this processcan incorporate a foreign gene
every time the bacteria replicates, the plasmid with its foreign gene also replicates Because the genetic code is universal, bacteria that contain recombinant DNA plasmids can transcribe and translate the foreign gene and produce large quantities of the desired protein. - 17What role do restriction enzymes and ligase enzymes playTo combine these ingredients, a piece of DNA must be spliced into the plasmid using a restriction enzyme and DNA ligase enzyme to glue the DNA back together
- 18Once a recombinant plasmid has been created, why is it placed into living bacterial cells?every time the bacteria replicates, the plasmid with its foreign gene also replicates