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| 694918715 | What are the four forms of viral genomes? | double stranded DNA, single stranded RNA, single stranded DNA, double stranded RNA | |
| 694918716 | What is a capsid? | protein shell enclosing viral genome capsids shape may be rod-shaped, polyhedral or more complex | |
| 694918717 | What is a capsomere? | protein subunits that build capsids. | |
| 694918718 | What are the components of the viral envelope? | 1.Host cell phospholipids and membrane proteins derived from membranes of the host cell. 2. proteins and glycoprotiens derived from viral origin. | |
| 694918719 | what is the role of the envelope in animal viruses? | glycoproteins which the cells of animals receive and allow entrance in membrane | |
| 694918720 | What property of viruses determines its attachment to a host cell membrane? | glycoproteins. between viral surface proteins and specific receptor molecules on the outside of the cell | |
| 694918721 | viruses are obligate intracellular parasites. what does this mean? | viruses have to function by invading and living in cells | |
| 694918722 | what is meant by host range? | extra particular virus can infect cells of only a limited number of species. ex: west nile has a broad host range... can infect insects, humans ex: measles have limited host range.. can only affect humans | |
| 694918723 | What components of the host cell does a virus use to reproduce itself? | nucleotides, enzymes, ribosomes, RNA, amino acids, and ATP | |
| 694918724 | How does a DNA virus reproduce its genome? | DNA polymerase | |
| 694918725 | How do most RNA viruses replicate their genome? | Virally encoded RNA polymerase | |
| 694918726 | What are bacteriophages? | A virus that infects a BACTERIA | |
| 694918727 | Distinguish between a virulent and temperate phages | V- replicates only by lytic cycle T-uses lysogenic and lytic cycle to reproduce | |
| 694918728 | What portion of a phage enters the host cell? how does it do this? | Binds glycoprotein to receptor of host cell DNA | |
| 694918729 | What are restriction enzymes? How do they prevent viral infections of bacteria? | metholate DNA in a resistant/restrictive way | |
| 694918730 | Why don't restriction enzymes destroy the DNA of the bacterial cells that produce them? | evolution. instead of lysing their host cells, many phages coesixt with them in a state called lysogeny | |
| 694918731 | what are three ways bacteria may win the battle against the phages? | 1. evolution 2. lysogeny 3. restriction enzymes | |
| 694918732 | What is a prophage? | when integrated into the bacterial chromosome, the viral DNA is known as a prophage. one prophage gene codes for a protein that prevents transcriptions of most of the other prophage genes | |
| 694918733 | Describe the lytic mode of bacteriophage reproduction | lytic cycle- phage replicative cycle that cumulates in death of the host cell. Each can infect healthy cell. LASt stage of infection | |
| 694918734 | Describe the lysogenic mode of bacteriophage reproduction | lysogenic cycle- allows replication of the phage genome without destroying the host | |
| 694918735 | what are 2 elements that nearly all animal viruses have? | 1. RNA genome have an envelope 2. Replicate in host cells | |
| 694918736 | What is a retrovirus? | equipped with an enzyme called reverse transcriptase which transcribes an RNA template into DNA, providing an RNA---> DNA information flow, opposite of the usual direction. | |
| 694918737 | How does HIV replicate their genome? | After HIV enters the host cell, its reverse transcriptase molecules are released into the cytoplasm, where they catalyze synthesis of viral DNA. Newly made viral DNA then enters the cell nucleus and interprets into the DNA of a chromosome. Provirus never leaves cell. | |
| 694918738 | Compare and contrast provirus and prophage | prophage leaves the cell. provirus never leaves the cell | |
| 694918739 | Plasmids | small circular DNA molecules found in bacteria and yeast. Exist apart from cells genome replicate independently from genome transferred between cells | |
| 694918740 | Transposons | DNA segments that move from one location to another within cells genome | |
| 694918741 | What are 3 ways that viruses make us ill? | 1. Damage/kill cells causing release of hydrolytic enzymes from lysosomes 2. cause infected cells to produce toxins 3. molecular components that are toxic, such as envelope proteins provirus affects mature cells. cells don't divide and can't be replaced | |
| 694918742 | What contribute to the sudden emergence of genes? | 1. mutation of existing viruses 2. Solution is isolated in human population 3. Spread of existing viruses from other animals | |
| 694918743 | Horizontal transmission | Plants infected from external source | |
| 694918744 | vertical transmission | plants inherits viral infection from a parent | |
| 694918745 | How do viruses spread throughout plant bodies? | plasmodestata-cytoplasm and connections that penetrate the walls between adjacent plant cells | |
| 694918746 | What is a viroid? | plant pathogen consisting of a molecule of naked, circular RNA a few hundred nucleotides long. A single molecule can be an infectious agent that spreads a disease. Ex: Mad cow | |
| 694918747 | Prions | infectious proteins that cause brain disease in animal species transmitted through food incubation period of at least ten years before symptoms develop virtually. | |
| 694918748 | Operon model | controls gene expression in bacteria | |
| 694918749 | Operator | the regulatory "switch"; a segment of DNA positioned within the promoter | |
| 694918750 | Operon | the entire stretch of DNA; includes the operator, the promoter, and the genes that they control | |
| 694918751 | Negative Operon control | gene that is normally on is turned off | |
| 694918752 | Positive Operon control | gene that is normally off is turned on | |
| 694918753 | What type of operon control do the regulation of the trp and lac operons involve? | Negative control, because operons are switched off by the active form of the repressor | |
| 694918754 | repressible operon | normally on; binding of a repressor to the operator shuts off transcription (trp operon) | |
| 694918755 | Inducible operon | normally off; an inducer inactivates the repressor and turns on transcription (lac operon) | |
| 694918756 | Repressible enzymes | function in anabolic pathways; their synthesis is repressed by high levels of the end product | |
| 694918757 | Inducible enzymes | function in catabolic pathways; their synthesis is induced by a chemical signal | |
| 694918758 | What protein is an activator of transcription, and subjects operons to positive control? | Catabolite Activator Protein (CAP) | |
| 694918759 | What is the preferred food source of E. Coli? | Glucose | |
| 694918760 | When glucose in E. Coli is scarce, what is activated by binding with cyclic AMP? | CAP | |
| 694918761 | When CAP attaches to the promoter of the lac operon, what occurs? | the affinity of RNA polymerase is increased, which accelerates transcription | |
| 694918762 | What happens in E. Coli when glucose levels increase? | CAP detaches from the lac operon, and transcription returns to a normal rate | |
| 694918763 | What is the purpose of CAP? | helps regulate other operons that encode enzymes used in catabolic pathways | |
| 694918764 | A Repressor is a product of what? | a separate regulatory gene | |
| 694918765 | Why can't transcription factors bind to a promote packaged in a nucleosome? | Nucleosomes block promoters | |
| 694918766 | Basal transcription factors | provide alignment for RNA polymerase; establish productive initiation | |
| 694918767 | Specific transcription factors (activators) | stimulate higher levels of transcription that basal levels | |
| 694918768 | Enhancers | binding site of specific transcription factors; DNA bends to form a loop, positioning the enhancer close to the promoter | |
| 694918769 | Three stages of embryonic development | cell division, cell differentiation, and morphogenesis | |
| 694918770 | Cell differentiation | the process by which cells become specialized in structure and function | |
| 694918771 | Morphogenesis | the physical processes that give an organism its shape | |
| 694918772 | Cytoplasmic determinants | The maternal substances in the egg that influence the course of early development by regulating the expression of genes that affect the developmental fate of cells. | |
| 694918773 | Induction | signal molecules form embryonic cells cause transcriptional changes in nearby target cells | |
| 694918774 | Cell determination | commits a cell to its final fate; before cell differentiation | |
| 694918775 | MyoD | one of several "master regulatory genes" that produce proteins that commit the cell to becoming skeletal muscle; transcription factor that binds to enhancers of various target genes | |
| 694918776 | Pattern formation | development of a spatial organization of tissues and organs (body plan) | |
| 694918777 | embryonic lethals | Mutations with phenotypes leading to death at the embryo or larval stage. | |
| 694918778 | Maternal effect genes | encode for cytoplasmic determinants that initially establish the axes of the body of Drosophila | |
| 694918779 | egg-polarity genes | Another name for maternal effect genes, these genes control the orientation (polarity) of the egg and the fly | |
| 694918780 | bicoid | A maternal effect gene that codes for a protein responsible for specifying the anterior end in Drosophila. | |
| 694918781 | Three ways proto-oncogenes can be changed into oncogenes | Movement of DNA within the genome, Amplification of a proto-oncogene, point mutations | |
| 694918782 | Movement of DNA within the genome causes? | if it ends up near an active promoter, transcription may increase | |
| 694918783 | Amplification causes? | increases the number of copies of the gene | |
| 694918784 | Point mutations cause? | an increase in gene expression | |
| 694918785 | TATA Box | aligns transcription factors within the promoter site |
