Meiosis/Mitosis Webquest
... many times as necessary to answer questions & summarize the first stage of meiosis. 1. At the start of this example how many chromosomes are in the cell? 2. What happens in the “S” phase to the chromosomes? 3. If a chromosome replicates but remains attached does it count as one or two chromosomes? 4 ...
... many times as necessary to answer questions & summarize the first stage of meiosis. 1. At the start of this example how many chromosomes are in the cell? 2. What happens in the “S” phase to the chromosomes? 3. If a chromosome replicates but remains attached does it count as one or two chromosomes? 4 ...
Organization of the Sea Urchin Egg Endoplasmic Reticulum and Its
... CA) ; this species was used because of the optical clarity of its eggs . Eggs and sperm were obtained by injection of0.5 M KCI into the coelomic cavity. The gametes were suspended in artificial sea water. Experiments were performed at 22-24°C . DiICIS (3) : 1,1'-dioctadecyl-3,3,3;3'-tetramethylindoc ...
... CA) ; this species was used because of the optical clarity of its eggs . Eggs and sperm were obtained by injection of0.5 M KCI into the coelomic cavity. The gametes were suspended in artificial sea water. Experiments were performed at 22-24°C . DiICIS (3) : 1,1'-dioctadecyl-3,3,3;3'-tetramethylindoc ...
What are plastids and where did they come from?
... a result of a symbiosis between a photosynthetic organism and a non-photosynthetic host, and this outrageous suggestion was further supported by the Russian botanist Constantin Mereschkowsky in 1905. Much debate continued through the twentieth century but was refocused as a hypothesis based on micro ...
... a result of a symbiosis between a photosynthetic organism and a non-photosynthetic host, and this outrageous suggestion was further supported by the Russian botanist Constantin Mereschkowsky in 1905. Much debate continued through the twentieth century but was refocused as a hypothesis based on micro ...
Chapter 18 Gene Expression
... • The regulatory “switch” is a segment of DNA called an operator usually positioned within the promoter • An operon is the entire stretch of DNA that includes the operator, the promoter, and the genes that they control Copyright © 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings ...
... • The regulatory “switch” is a segment of DNA called an operator usually positioned within the promoter • An operon is the entire stretch of DNA that includes the operator, the promoter, and the genes that they control Copyright © 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings ...
2.2 Membrane Structure and Functions
... Keeping the lining of the lungs and intestinal tract hydrated is critical to its proper functioning. In individuals with CF, the Cl- channel of CFTR malfunctions and water is retained within the cells. A lack of moisture in the mucus lining makes the mucus very thick. When this happens in the lungs, ...
... Keeping the lining of the lungs and intestinal tract hydrated is critical to its proper functioning. In individuals with CF, the Cl- channel of CFTR malfunctions and water is retained within the cells. A lack of moisture in the mucus lining makes the mucus very thick. When this happens in the lungs, ...
Regulation of Gene Expression
... DNA Methylation • DNA methylation, the addition of methyl groups to certain bases in DNA, is associated with reduced transcription in some species • DNA methylation can cause long-term inactivation of genes in cellular differentiation • In genomic imprinting, methylation regulates expression of eit ...
... DNA Methylation • DNA methylation, the addition of methyl groups to certain bases in DNA, is associated with reduced transcription in some species • DNA methylation can cause long-term inactivation of genes in cellular differentiation • In genomic imprinting, methylation regulates expression of eit ...
Gene transcription is coordinated with, but not dependent on, cell
... uncharacterized. To examine this relationship, we combined single-molecule RNA imaging with time-lapse microscopy to generate high-resolution measurements of transcriptional dynamics in Caenorhabditis elegans embryogenesis. We found that globally slowing the overall development rate of the embryo by ...
... uncharacterized. To examine this relationship, we combined single-molecule RNA imaging with time-lapse microscopy to generate high-resolution measurements of transcriptional dynamics in Caenorhabditis elegans embryogenesis. We found that globally slowing the overall development rate of the embryo by ...
Snapshots of RNA polymerase II transcription initiation
... Transcription complex assembly Reconstituted in vitro transcription systems have been essential for establishing the contacts between various transcription factors. However, it can be argued that crude extracts more closely resemble nuclear conditions in terms of factor ratios and preassembled compl ...
... Transcription complex assembly Reconstituted in vitro transcription systems have been essential for establishing the contacts between various transcription factors. However, it can be argued that crude extracts more closely resemble nuclear conditions in terms of factor ratios and preassembled compl ...
Chapter 4 Review Questions
... 39. The statement “Cells are produced only from existing cells” is part of the ____________________. 40. The ratio of surface area to ____________________ puts limitations on a cell’s size. 41. Eukaryotic cells are much larger and have more specialized functions than prokaryotic cells because they c ...
... 39. The statement “Cells are produced only from existing cells” is part of the ____________________. 40. The ratio of surface area to ____________________ puts limitations on a cell’s size. 41. Eukaryotic cells are much larger and have more specialized functions than prokaryotic cells because they c ...
9/18/08 Transcript I
... of 3rd and 4th lectures. All lectures are in one of these two lectures. They are mixed. So just listen carefully. You will have a copy of these available to you. Another question: paraphrase: Is there a PowerPoint with your notes that we can get? A: It’s written in your book. You see when you get a ...
... of 3rd and 4th lectures. All lectures are in one of these two lectures. They are mixed. So just listen carefully. You will have a copy of these available to you. Another question: paraphrase: Is there a PowerPoint with your notes that we can get? A: It’s written in your book. You see when you get a ...
Microbiology An Introduction 10e Tortora, Funke and Case Outline
... Eukaryotic cells are highly compartmentalized. A large surface-to-volume ratio, as seen in smaller prokaryotic cells, means that nutrients can easily and rapidly reach any part of the cells interior. However, in the larger eukaryotic cell, the limited surface area when compared to its volume means n ...
... Eukaryotic cells are highly compartmentalized. A large surface-to-volume ratio, as seen in smaller prokaryotic cells, means that nutrients can easily and rapidly reach any part of the cells interior. However, in the larger eukaryotic cell, the limited surface area when compared to its volume means n ...
The Myriad Roles of Anillin during Cytokinesis Alisa J. Piekny1 and
... If the interaction between Anillin and myosin does not serve the purpose of recruitment in metazoan cells, what is its role? One of Anillin’s key functions is to “organize” myosin. Drosophila Anillin is required for the organization of myosin into discrete, intact rings throughout the cellularizati ...
... If the interaction between Anillin and myosin does not serve the purpose of recruitment in metazoan cells, what is its role? One of Anillin’s key functions is to “organize” myosin. Drosophila Anillin is required for the organization of myosin into discrete, intact rings throughout the cellularizati ...
cell cycle pp
... In unicellular organisms, division of one cell reproduces the entire organism Cell division enables multicellular eukaryotes to develop from a single cell and, once fully grown, to renew, repair, or replace cells as needed Cell division is an integral part of the cell cycle, the life of a cel ...
... In unicellular organisms, division of one cell reproduces the entire organism Cell division enables multicellular eukaryotes to develop from a single cell and, once fully grown, to renew, repair, or replace cells as needed Cell division is an integral part of the cell cycle, the life of a cel ...
Epigenetic Regulation of Higher Order Chromatin
... 1.1.2 Principles of epigenetic regulation A central question addresses the functional consequences of the different epigenetic marks. In other words, is there a universal code that would associate certain epigenetic marks or a certain combination of marks with specific nuclear function, such as rep ...
... 1.1.2 Principles of epigenetic regulation A central question addresses the functional consequences of the different epigenetic marks. In other words, is there a universal code that would associate certain epigenetic marks or a certain combination of marks with specific nuclear function, such as rep ...
The Plant Secretory Pathway: An Essential
... yellow fluorescent protein (YFP)–CESA6-positive compartments bound to microtubules were observed under treatment with the cellulose synthesis inhibitor isoxaben (Gutierrez et al. 2009). When oryzalin and isoxaben were used, YFP–CESA6 signal was not detected, presumably as a consequence of oryzalin-m ...
... yellow fluorescent protein (YFP)–CESA6-positive compartments bound to microtubules were observed under treatment with the cellulose synthesis inhibitor isoxaben (Gutierrez et al. 2009). When oryzalin and isoxaben were used, YFP–CESA6 signal was not detected, presumably as a consequence of oryzalin-m ...
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... sists of removing an adenosine residue from the 28S RNA of the large ribosomal subunit (48 –50). Although this does not result in disruption of the RNA backbone, elongation factors are unable to bind properly to the modified ribosomes and protein synthesis stops. The A-chain of cholera toxin is an A ...
... sists of removing an adenosine residue from the 28S RNA of the large ribosomal subunit (48 –50). Although this does not result in disruption of the RNA backbone, elongation factors are unable to bind properly to the modified ribosomes and protein synthesis stops. The A-chain of cholera toxin is an A ...
Gene - Hal
... In order to confirm the presence of functional promoter regulatory elements, the putative promoter region (about 2.5 kb) plus 66 bp of exon 1 was ligated 5′ to a luciferase reporter gene (Mist WT-Luc), and the activity of the promoter was tested by transient DNA transfections in NIH3T3 fibroblasts a ...
... In order to confirm the presence of functional promoter regulatory elements, the putative promoter region (about 2.5 kb) plus 66 bp of exon 1 was ligated 5′ to a luciferase reporter gene (Mist WT-Luc), and the activity of the promoter was tested by transient DNA transfections in NIH3T3 fibroblasts a ...
Update on the Notochord Including its Embryology
... formation of the vertebral column can emit repulsive signals excluding notochord cells and cause them to occupy the space between the forming vertebrae [12]. There are many signaling pathways that may play a role such as eph/ephrin or robo/slit [12]. This notochordal tissue will go on to develop int ...
... formation of the vertebral column can emit repulsive signals excluding notochord cells and cause them to occupy the space between the forming vertebrae [12]. There are many signaling pathways that may play a role such as eph/ephrin or robo/slit [12]. This notochordal tissue will go on to develop int ...
mutant alleles of polymitotic that disrupt the cell cycle
... nuclear morphology is abnormal in these cells. The chromatin is more diffuse than that in wild-type cells at a similar stage (compare to Fig. 1C). In Fig. 2B, two tetrad cells show abnormal interphase nuclear microtubule arrays. However, the other two cells are separated by a phragmoplast. In wild-t ...
... nuclear morphology is abnormal in these cells. The chromatin is more diffuse than that in wild-type cells at a similar stage (compare to Fig. 1C). In Fig. 2B, two tetrad cells show abnormal interphase nuclear microtubule arrays. However, the other two cells are separated by a phragmoplast. In wild-t ...
- Wiley Online Library
... the latter of which contains the GTP binding region (Díaz et al., 2001) (also called tubulin signature motif or T3 loop). Neither of the two tubulin/FtsZ domains (PF00091 and PF03953) was present. In conclusion, sequence analysis indicated that kustd1438 is a large structural protein with predicted ...
... the latter of which contains the GTP binding region (Díaz et al., 2001) (also called tubulin signature motif or T3 loop). Neither of the two tubulin/FtsZ domains (PF00091 and PF03953) was present. In conclusion, sequence analysis indicated that kustd1438 is a large structural protein with predicted ...
Nucleolar targeting of BN46/51 - Journal of Cell Science
... basal body complex, monoclonal antibodies (mAbs) were developed against proteins derived from a basal body fraction (Trimbur and Walsh, 1992). The mAb BN5.1 was identified based on its specific reaction to the basal body region. BN5.1 also reacts with the large central nucleolus of both amebae and f ...
... basal body complex, monoclonal antibodies (mAbs) were developed against proteins derived from a basal body fraction (Trimbur and Walsh, 1992). The mAb BN5.1 was identified based on its specific reaction to the basal body region. BN5.1 also reacts with the large central nucleolus of both amebae and f ...
Chapter 8. Movement across the Membrane
... Membrane Proteins Proteins determine most of membrane’s specific functions ...
... Membrane Proteins Proteins determine most of membrane’s specific functions ...
Cell nucleus
In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel) is a membrane-enclosed organelle found in eukaryotic cells. Eukaryotes usually have a single nucleus, but a few cell types have no nuclei, and a few others have many.Cell nuclei contain most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nucleoskeleton (which includes nuclear lamina), a network within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.Because the nuclear membrane is impermeable to large molecules, nuclear pores are required that regulate nuclear transport of molecules across the envelope. The pores cross both nuclear membranes, providing a channel through which larger molecules must be actively transported by carrier proteins while allowing free movement of small molecules and ions. Movement of large molecules such as proteins and RNA through the pores is required for both gene expression and the maintenance of chromosomes. The interior of the nucleus does not contain any membrane-bound sub compartments, its contents are not uniform, and a number of sub-nuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes. The best-known of these is the nucleolus, which is mainly involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA.