Concept explainers
To review:
The experiment that can distinguish between the motions of bacterial flagella and eukaryotic flagella and to prove that the flagella rotate.
Introduction:
The advancement in the technologies of microscopy leads to the development of more advanced microscopes. They are able to detect/resolve cellular structures that cannot be detected by earlier versions of microscopes. The limit of resolution, as well as detection, of such microscopes, are much more as compared to the earlier ones.
The detection of bacterial flagella depends upon the correct positioning of the specimen. In case the flagella get hidden under the coverslip, then they may not be visible under the light microscope. This can be resolved by using a dark field optics microscope. In these microscopes, the light entering from the source is controlled with the help of “spider� shaped rings. This enhances the contrast between the specimen and the surroundings.
In order to deduce the type of motion produced by the flagella, the specimen must be tied to the slide. Bacteria can be tied to the slide by covering the slide with an anti-flagellin antibody. After this, the motion of flagella must be observed under the microscope by using video microscopy. In case the flagella show rotatory motion, then the cell body will also begin to rotate and if the flagella show motion in a whiplike fashion, then the tied cell will move back and forth.
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Microbiology: An Evolving Science (Fourth Edition)
- Identify Three subtypes of polar arrangement where the flagella are attached at one or both ends of the cell.arrow_forwardWhich one of the following statements is the most accurate comparison of human, bacterial and fungal cells? (May answer is LETTER C but i am not sure hope somebody can help me ) A. Human and fungal cells have similar ribosomes, whereas bacterial ribosomes are different. b. Human and fungal cells have similar cell wall, in contrast to bacteria whose cell wall contains peptidoglycan. c. Human cells undergo mitosis, whereas neither bacteria nor fungi do. d. Human and bacterial cells have plasmids, whereas fungal cells do not have.arrow_forwardAll of the following are characteristics of the bacterial flagellum except: Select one: a. It has a hook-like insertion to a basal body in the cell wall. b. It is composed of protein c. It is used in conjugation d. Counterclockwise rotation moves bacteria forward All the following are characteristics of prokaryotes except: Select one: a. Prokaryotes have cell wall b. Prokaryotes have ribosomes c . Prokaryotes have organelles d. Prokaryotes lack a nucleus e. Prokaryotes have genesarrow_forward
- Draw to scale the outline of two spherical cells, one a bacterium with a diameter of 1 μm, the other an animal cell with a diameter of 15 μm. Calculate the volume, surface area, and surface-to-volume ratio for each cell. how would the latter ratio change if you included the internal membranes of the cell in the calculation of surface area (assume internal membranes have 15 times the area of the plasma membrane)? (the volume of a sphere is given by 4πr3/3 and its surface by 4πr2, where r is its radius.) discuss the following hypothesis: “internal membranes allowed bigger cells to evolve.”arrow_forwardGram-positive (+) and gram-negative (-) bacteria are characterized by differences in a. the cell wall: gram+ have peptidoglycan, gram– have pseudopeptidoglycan. b. the plasma membrane: gram+ have ester-linked lipids, gram–have ether-linked lipids. c. the cell wall: gram+ have a thick layer of peptidoglycan and gram– have an outer membrane. d. chromosomal structure: gram+ have circular chromosomes, gram– have linear chromosomes.arrow_forwardWhat is the rate-limiting step in cytoskeletal filament assembly? A. Nucleation B. Extension C. Branching D. Disassemblyarrow_forward
- If you compared two motile bacterial species and determined one was considerably more motile than the other, which arrangement of flagella would you expect to be associated with the highly motile species? How would you confirm this?arrow_forwardDescribe the following as seen under the compound microscope. Endoplasmic reticulum Ribosome Centrosomearrow_forwardWhy is the rigid layer of the bacterial cell wall calledpeptidoglycan?arrow_forward
- Which of the following is not associated with eukaryotic cells? a) Nucleoli. b) Plastids. c) Plasmids. d) Plasmodesmata. e) Basal bodies. Which paired items are structurally identical to one another? a) Eukaryotic and prokaryotic ribosomes. b) Centrioles and basal bodies. c) Plastids and mitochondria. d) Eukaryotic and prokaryotic flagella. Which statement is not true? a) Plant cells are eukaryotic. b) Cholorplasts are typically found in the roots of plants. c) Plasmodesmata allow plant cells to share cytoplasm with one another facilitating movement of materials from one cell to another. d) Endoplasmic reticula and golgi complexes work together in the secretion of products from a cell. Which structure is not found in plant cells? a) Mitochondria. b) Plastids. c) Centrioles. d) Golgi bodies. e) Mark e if all are found in plant cells. Which of the following is not found in animal cells? a) Mitochondria. b)…arrow_forwardWhat cell types would be able to grow on the ECM in the following situations?a) Streptomycin was not added to the ECM.b) The ECM contains thiamine.c) The ECM contains all 20 amino acids and all 5 nitrogenous nucleic acid bases. Reminder: ECM = minimal medium + glucose + has streptomycin antibioticarrow_forwardWhich of the following statements applies to all three major classes of cytoskeletal polymers (microtubules, actin filaments and intermediate filaments)? They have intrinsic polarity They assemble from protein subunits synthesized on free polyribosomes They add subunits only at their ends They are involved in cell motility Their constituent proteins are tissue specificarrow_forward
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning