Concept explainers
The unicellular alga Chlamydomonas reinhardtii has two flagella assembled from tubulin proteins. If a researcher changes the pH from approximately neutral (their normal growing condition) to pH 4.5, Chlamydomonas cells spontaneously lose their flagella. After the cells are returned to neutral pH, they regrow the flagella—a process called reflagellation. Assuming that you have deflagellated Chlamydomonas cells, devise experiments to answer the following questions:
Do new tubulin proteins need to be made for reflagellation to occur, or is there a reservoir of proteins in the cell?
Is the production of new mRNA for the tubulin proteins necessary for reflagellation?
What is the optimal pH for reflagellation?
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Biology: The Dynamic Science (MindTap Course List)
- You treat a cell with a fluorescently-labelled antibody that recognizes microtubules, and you observe what appears to be a spindle apparatus. Is the cell a prokaryote or a eukaryote? Explain. Some archaebacteria species live in extremely high-salt environments. Cite a specific example of protein modification that has allowed these bacteria to accomplish this.arrow_forwardBriefly discuss the structure of plasmodesmeta. How does it control the passage of molecules between two cells?arrow_forwardA fluorescent molecule of 2000 daltons is microinjected into a single cell of an epithelial layer. When the layer is examined in a fluorescence microscope, the molecule remains confined to that cell. However, when a fluorescent molecule of 800 daltons is injected into a single cell of an epithelial layer, it quickly appears in the adjacent cells. Which of the following is responsible for the spread of the smaller molecule? 1. A) Desmosomes (maculae adherentes) 2. B) Focal contacts 3. C) Gap junctions 4. D) Intermediate junctions 5. E) Tight junctions (zonulae occludentes)arrow_forward
- Hello, i understand the question, but i only need to know which option is right, no need for explanation. thanks in advance.arrow_forwardWhich of the following regarding microtubules is LEAST correct? A)Microtubules do not have important functions in neurons B)Microtubules are important for anterograde axoplasmic transport C)No answer text provided. D)Microtubules are important for maintaining the structure of the neuron E)Microtubules are important for retrograde axoplasmic transportarrow_forwardIf the diameter of the field of view in your microscope is 2 mm under low power, and one Bacillus cell is 2 µm long, how many Bacillus cells would it take to reach all the way across this field of view? If yeast cells measure 10 µm in length, how many yeast cells would it take to reach across this same field of view?arrow_forward
- Measure the length of Cell X using the ruler in Microsoft Word. Assuming the actual length to be 3 um, calculate the magnification. Show your complete solution. Based on Figure 1, what internal organization can be distinguished in cell X? Why? Based in Figure 1, can you see a limiting membrane? Can you deduce its presence? Why or why not?arrow_forwardA clinical microbiologist is studying a microbe that can cause infections and gastrointestinal disease in humans, and which can also survive and reproduce in mice. A dormant cyst form of the microbe infects human hosts through fecal-oral transmission if they come in contact with mouse droppings and don’t wash their hands before eating. The organism grows in long filaments when grown at 20-28 deg C, and forms round/ovoid cells when grown at temperatures above 28 deg C. Sexual reproduction (fusion of haploid gametes) occurs in both humans and mice. A cell wall is present, and cells contain nuclei. This microbe could be which of the following? Bacterium Fungus Virus Protozoanarrow_forwardExplain (using the correct terminology and drawing an image) what happens to the cells in the following environments: A human blood cell (0.9% salt) is placed in a saltwater tank (27.5% salt). - A bacterial cell with 35% organic material in their cytoplasm is living in a tank filled with 35% sulfur. - A freshwater plant cell (75% water) is living in a pond that floods over.arrow_forward
- What are the side effects of Leakage of charge (predominately K1) across theplasma membrane?arrow_forwardFor which of the following apply: the extracellular space is eliminated here near the surface between two cells. A) Zonula adherens B)Zonula occluded C) Desmosome D) Gap junction E) Hemidesmosomearrow_forwardCytokinesis in plant cells is different than cytokinesis in animal cells. a) Explain why it has to be different, andb) briefly describe the processes in the two different cell types.arrow_forward