What is the total magnification of a microscope with a 10X ocular and a 100X oil immersion objective?
What is the total magnification of a compound light microscope?
To calculate the total magnification of the compound light microscope multiply the magnification power of the ocular lens by the power of the objective lens. For instance, a 10x ocular and a 40x objective would have a 400x total magnification. The highest total magnification for a compound light microscope is 1000x.
How does the compound microscope magnify an object?
A microscope is an instrument that can be used to observe small objects, even cells. The image of an object is magnified through at least one lens in the microscope. This lens bends light toward the eye and makes an object appear larger than it actually is.
Why is it necessary to do an Endospore stain to verify the presence of endospores?
Why is it necessary to do an endospore stain to verify the presence of endospores? An endospore stain is necessary as it is the only type of stain that will penetrate the endospore’s wall. This allows the endospores to be differentiated from the inclusions of stored material.
Are spores easy to kill?
Bacterial spores are extremely durable and can be very difficult to destroy even under extreme temperatures. Once favorable conditions return, the protective proteins dissolve the spore coating and the vegetative cell functions resume.
What is the difference between a vegetative cell and an Endospore?
A) Vegetative cells are metabolically active, whereas endospores are dormant.
Do vegetative cells have high water content?
The high water content of bacterial vegetative cells may favor, within the cytoplasm, the production of a variety of harmful radicals, which enhance radiation injury. These radicals are not as readily formed in the spores, which are dormant structures with little or no free water in their cytoplasm.
Do vegetative cells require autoclave for destruction?
Autoclaves. Autoclaves rely on moist-heat sterilization. They are used to raise temperatures above the boiling point of water to sterilize items such as surgical equipment from vegetative cells, viruses, and especially endospores, which are known to survive boiling temperatures, without damaging the items.
Are vegetative cells heat resistant?
Although pasteurization is known to inactivate the vegetative cells, spores of B. cereus are known to be highly heat resistant and are usually unaffected by physical, chemical and biological factors (Gaillard et al. 1998; González et al. 1999).
What kills vegetative cells?
What is the function of vegetative cells?
In pollen grains, the known function of the vegetative cell is to extend a pollen tube to transport the two sperm cells to the embryo sac for fertilization.
What is vegetative cell in microbiology?
The normally-growing cell that forms the endospore is called a vegetative cell. Spores are metabolically inactive and dehydrated. They can remain viable for thousands of years. When spores are exposed to favorable conditions, they can germinate into a vegetative cell within 90 minutes.
How do vegetative bacterial cells divide?
Most bacteria rely on binary fission for propagation. Conceptually this is a simple process; a cell just needs to grow to twice its starting size and then split in two. Before binary fission occurs, the cell must copy its genetic material (DNA) and segregate these copies to opposite ends of the cell.
What happens during sporulation?
Essentially, sporulation refers to the formation of spores from vegetative cells during unfavorable environmental conditions. As such, it may be described as an adaptive response that allows the organism to survive given adverse conditions (radiation, extreme heat or cold, lack of nutrition etc).
Are endospores Gram positive or negative?
Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries.
Why are spores so difficult to destroy?
DPA has the ability to cross-link with calcium that is embedded within the spore coat. The calcium cross-links contribute to the heat resistance of the bacterium making for a hard barrier to penetrate. The endospore makes it difficult to kill bacteria.
Can endospores be detected by Gram staining?
Although endospores themselves are resistant to the Gram stain technique, bacterial cells captured in the process of creating these structures can be stained. In this case, the endospores are seen as clear oval or spherical areas within the stained cell.
What do endospores look like in a Gram stain?
When viewed unstained, endospores of living bacilli appear edged in black and are very bright and refractile. Endospores strongly resist application of simple stains or dyes and hence appear as nonstaining entities in Gram-stain preparations. However, once stained, endospores are quite resistant to decolorization.
What is the principle of spore stain?
Principle of Endospore Staining In the Schaeffer-Fulton`s method, a primary stain-malachite green is forced into the spore by steaming the bacterial emulsion. Malachite green is water soluble and has a low affinity for cellular material, so vegetative cells may be decolourized with water.
What diseases can be diagnosed with the Endospore stain?
Infectious diseases such as anthrax, tetanus, gas gangrene, botulism, and pseudomembranous colitis are transmitted to humans by endospores.
What kind of bacteria can form spores?
Spore-forming bacteria include Bacillus (aerobic) and Clostridium (anaerobic) species. The spores of these species are dormant bodies that carry all the genetic material as is found in the vegetative form, but do not have an active metabolism.
Can viruses form spores?
According to Bandea’s hypothesis, the infected cell is the virus, while the virus particles are ‘spores’ or reproductive forms. His theory was largely ignored until the discovery of the giant mimivirus, which replicates its DNA genome and produces new virions in the cytoplasm within complex viral ‘factories’.
How do you kill spores?
A process called sterilization destroys spores and bacteria. It is done at high temperature and under high pressure. In health care settings, sterilization of instruments is usually done using a device called an autoclave.
Which bacteria Cannot produce spores?
The Firmicutes are a phylum of bacteria, most of which have Gram-positive cell wall structure and some of which do not produce spores.
How do spores cause disease?
Spores are inhaled and deposited into the lung tissue, where they proceed to germinate and spread through lymph nodes, rapidly causing systemic disease, massive tissue damage, shock and death (14).
Are spores dangerous?
Mold spores can cause health issues by triggering allergies or asthma attacks. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on to survive. Molds can reproduce in any moist place. They can grow on wood, paper, carpet, foods and other surfaces.
Does chlorine kill spores?
However, chlorine has the advantage of being able to kill bacterial spores, a dormant form of bacteria that can activate to cause infection. Chlorine is a powerful disinfectant that can kill most bacteria, viruses, and parasites when it is added to water.
What disease is caused by reactivated bacterial spores?
Similarly, spores contribute to the transmission of many clostridial diseases, including botulism, tetanus, gas gangrene, Clostridium difficile infection, and C.