EXAM 3 BIOS 100

People magazine recently reported that "Henrietta Lacks' Family to Sue for Compensation for Her Medically Revolutionary Cells." What made the cells revolutionary was
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People magazine recently reported that "Henrietta Lacks' Family to Sue for Compensation for Her Medically Revolutionary Cells." What made the cells revolutionary was
their ability to live and grow outside the body
Jacob and Monod studied the lac operon as a model for understanding gene regulation. Their innovation was the discovery that a protein binding to a specific DNA sequence could result in
repression or turning off expression of adjacent gene(s)
Which of the following terms describes the DNA-protein complexes that look like beads on a string?
nucleosome
Which of the following regulatory DNA sequences might be located thousands of nucleotides away from the transcription start site of a eukaryotic gene?
Enhancer
Which of the following are used to regulate gene expression and function?
transcriptional control
Translational control
Post-translational modification
Alloftheabove
In alternative splicing
One gene can produce many slightly different variants of a protein
Which mitotic phase is the one where the chromosomes condense and the mitotic spindle begins to form?
prophase
Which of the following does not occur during mitosis?
replication of the DNA
The initial segregation of chromosomes during Anaphase A of mitosis is driven by
shortening of kinetochore microtubules
Later during anaphase B we see a contribution of ______________________ to separation of chromosomes
widening of the distance between spindle poles
Cyclin dependent kinase (CDK) isan enzyme that attaches phosphate groups to specific target proteinsA group of cells is assessed for DNA content immediately following mitosis and is found to have an average of 13 picograms of DNA per nucleus. How many picograms would be fond at the end of S phase and the end of G2?26; 26The retinoblastoma protein Rb is called a tumor suppressor becauseit prevents cell division unless suitable growth factors are presentPausing the cell cycle, for example when chromosomes are not yet correctly attached to the spindle apparatus, is calledcheckpoint controlChromatophores, the cells in fish scales that give them color and patterns, respond to ephinephrine in the fight or flight response. When epinephrine is present, say when a predator of our fish is present, the protein dynein is likely to be active and helping to mediate the loss of color that helps our fish avoid being eaten. Which of the following proteins would interfere with the fight or flight response if it remained active?kinesinWhich of the following statements about Okazaki fragments in E. coli is true?they are formed on the lagging strand of the replicating DNADNA replication is achieved by elongating short RNA polymers that complement the template strand. These RNAs are known asprimersTelomerase is an enzyme thatprotectsendsofchromosomesfromunder-replicationofDNAThe enzyme that connects small pieces of replicated chromosome into long continuous strands is calledDNA ligaseThe term "allele" refers todifferent versions of the same geneThe cell below represents a 2n = 6 cell in what stage of divisionmetaphase I of meiosisWhat is the ploidy of cells that have 2 sets of chromosomes?2nWhich of the following creates new combinations of alleles along each chromosome:crossingoverthe reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain differentsets of regulatory proteinsHarold Weintraub discovered myoD as the master transcriptional regulator for muscle cell differentiation. He did it by demonstrating thatexpression of myoD in non-muscle cells (fibroblasts) led them to synthesize and accumulate muscle specific proteinsA ___________________________ mutation is the class of mutation in which body parts develop in the wrong location, such as when a fly grows legs where its antennae should be,homeoticThe developmental program where cell death makes a beneficial contribution to the final body plan is calledapoptosisThe most remarkable human stem cells are the ones that can differentiate into any of the 210 different cell types found in our bodies. These stem cells are calledpluripotentYamanaka and colleagues recently won a Nobel prize for their groundbreaking work showing that adult human skin cells can be de-differentiated to a state like embryonic stem cells (able to form any of the 210 differentiated cells of an adult human). To achieve this Yamanaka and colleaguesexpressed four transcription factors that are not normally expressed in adult skin, but are expressed in ES cellsStem cells are normally found in the human bodythroughoutchildhoodandadulthoodA problem with developing therapeutic uses of embryonic stem (ES) cells to treat human disease is thatit is illegal to destroy human embryos for research funded by the federal government to better understand how to use them. ES cells often form tumors when introduced into adult animals ES cells from a random human embryo are likely to be recognized as foreign by the recipient's immune system. AlloftheaboveThe remarkable motility of Listeria in the cytoplasm of infected human cells provides a simple way for the bacteria tospread to neighboring cells without entering the extracellular spaceListeria infection hijacks machinery in the host cell that is normally used by cells foramoeboid cell movement (cell crawling)The cell structure that stitches neighboring cells together by virtually eliminating space between them, thus preventing materials from passing between cells, is calledatightjunctionThe "anchoring junction" is like a spot weld between neighboring cells that also provides an anchoring site for keratin fibers that reinforce cell sheets. These junctions are also called _______________________________.desmosomesG protein-coupled receptors are involved in transmitting signals in biological systems. The G protein corresponds toan intracellular messenger that relays the signal to its target inside the cellThe driving force for crawling of animal cells over a substrate comes fromactivation of actin polymerization toward the leading edge of the cellThe driving force for spindle pole separation during mitosis comes fromdynein action on astral microtubules near the plasma membrane a kinesin family protein that links overlapping polar microtubules near the center of the spindleAdult stem cell therapy using cells harvested from a patient's own fat tissue, as in the procedure used to treat back pain in US Secretary of Energy Rick Perry,is currently banned by the FDA pending further investigation into safety and effectivenessThis procedure is probably not legal, but if you removed the nucleus from an unfertilized human egg cell and then inject the nucleus from a male's sperm cell into that egg, what will happen?the cell will not produce any new viable diploid cells