What Features Did The Cells You Observed Have In Common?
What features did the cells you observed have in common? … Some features in common: nuclei cytoplasm and cell membranes. Some different features: cell walls chloroplasts and cilia/flagella.
How would you expect both positive and negative results to be affected if you were to add glucose?
What happens during the Starch Hydrolysis test? … How would you expect both positive and negative results to be affected if you were to add glucose to the medium in the starch hydrolysis test? The glucose would cause the starch breakdown to be slower resulting in a false negativ. What is the DNA Hydrolysis DNase test?
Did you get growth on in the sterile NB?
Yes a slight density difference is noticed and as more cells are transferred onto the NB tubes from nutrient broth (NB) and Nutrient agar (NA) slants. The different turbidity in NB is due to different concentrations of bacterial cells present in the broth.
What would happen if you forgot to take the lid off the plate before exposing the cells to UV?
What would you expect to happen if you forgot to remove the lids on all your plates when you put them under the UV lamp? … The UV light will not damages the DNA and the microorganisms will grow. Since UV light will not go through plastic glass and many other materials.
What do you expect to see on the MSA and Na plates?
Growth on the MSA and NA plates was recorded as “good growth” “poor growth” or “no growth”. These are qualitative and at least for the first two subjective terms. … This means that bacteria that are sensative to salt would grow on the NA but not on the MSA.
What do the three organisms you just observed have in common?
What features did the cells you observed have in common? … Some features in common: nuclei cytoplasm and cell membranes. Some different features: cell walls chloroplasts and cilia/flagella.
What is the importance of having a positive and negative control when using Tributyrin Agar?
What is the importance of having a positive and a negative control when using Tributyrin Agar? A positive control will show what clearing looks like against that opacity. – Without proper opacity it would be impossible to see clearing produced by a lipase + organism resulting in a false negative.
What is the term for a growth of cells descended from an original cell as observed on a culture plate quizlet?
What is the term for a growth of cells descended from an original cell as observed on a culture plate? colony.
Do you think the broth or the slant will give you the better smear?
More difficult to see in broth because you can only see if growth occurred on the top or bottom etc. Better in slant because you can observe different growth patterns.
How would a microbiologist determine if their transfers had been successful?
How do you know your transfer to agar slants were successful? Success is presence of growth. If any of your transfers were unsuccessful suggest possible errors that may have been made in the transfer process. Failure is no growth or growth of a wide variety of colonies signaling contamination.
What did you conclude from observing the plate that was exposed to UV radiation with the lid on?
It was a control because visible light does no have UV. **What did you conclude from observing the plate that was exposed to UV radiation with the lid on? It had poor penetrating ability.
What are the precautionary measures that must be observed to ensure that the culture media are free from contamination?
- Wear gloves lab-coats and use hoods. …
- Use your hood correctly. …
- Clean your incubator and water bath regularly. …
- Spray EVERYTHING with ethanol or IMS. …
- Minimize exposure of cells to non-sterile environments.
Why was it necessary to remove the lid from the petri dish before exposing the sample?
Why do you remove the cover prior to exposing the dish to UV light? UV light does not penetrate well and can not penetrate the plastic.
What can you conclude about the pictured bacteria?
What does an MSA plate test for?
What makes MSA selective?
Which type of organisms are usually observed with light microscopes?
- bright field. The specimen is usually stained and observed while illuminated useful for observation of the gross morphological features of bacteria fungi algae and protozoa.
- dark field. …
- fluorescence. …
- phase contrast.
What are the 5 characteristics of bacteria?
- Single-Celled. Perhaps the most straightforward characteristic of bacteria is their existence as single-celled organisms. …
- Absent Organelles. …
- Plasma Membrane. …
- Cell Walls. …
- DNA.
What are the common biochemical tests used in the identification of bacteria?
- Catalase Test.
- Mannitol Salt Agar (MSA)
- Blood Agar Plates (BAP) Streak-stab technique.
- Taxos P (optochin sensitivity testing)
- Taxos A (bacitracin sensitivity testing)
- CAMP Test.
- Bile Esculin Agar.
- Nitrate Broth.
What does the enzyme Casease have in common with amylase?
What does the enzyme casease have in common with amylase? They are both exoenzymes. Casease hydrolyzes casein while amylase hydrolyzes starch. Some microbiologists recommend incubating this medium at 37C along with an uninoculated control and then transferring all tubes to the refrigerator prior to reading them.
What does a positive lipase test look like?
What advantage would a lipase organism?
Ease of handling broad substrate tolerance high stability towards temperatures and solvents high enantioselectivity convenient commercial availability and reusability are the key advantages of choosing lipase as a biocatalyst in a huge number of organic transformations.
Why do you think there is a lag before the bacteria cells start growing in fresh media quizlet?
There are not enough nutrients for the bacteria to grow and growth is delayed until there are some dead cells to cannibalize.
Which factor is the most likely to affect the growth and survival of micro organisms?
Warmth moisture pH levels and oxygen levels are the four big physical and chemical factors affecting microbial growth. In most buildings warmth and moisture are the biggest overall issues present. Dampness is a big player in the growth of fungi. Just like any living thing water is essential to the life of microbes.
Do bacteria exhibit synchronous or nonsynchronous growth?
Synchronous growth is the growth of bacteria such that all the bacteria are at the same stage in their growth cycle (e.g. exponential phase stationary phase).
Why are growth characteristics more useful on agar plates than on agar slants?
List some reasons why growth characteristics are more useful on agar plates than on agar slats. The main reason is that on agar plates growth is in individual colonies not confluent as on slants. While color and opacity are visible on each some features such as elevation are less obvious.
What is the difference between making a smear from broth compared to agar?
The only difference between broth and agar media is that broths do not contain an agar component. We use broth tubes primarily for specific assays or (rarely) for bacteria that will not form colonies on a solid surface.
What is the advantage of the Gram stain over the simple stain?
What is the advantage of the Gram stain over a simple stain such as methylene blue? Gram staining highlights different bacteria types through the use of special dyes. It aids in the diagnosis of a specific organism and tells the difference between gram negative and gram positive bacteria.
What are some of the aseptic techniques observed in the microbial handling in the laboratory?
- Always wipe your hands and work area with 70% ethanol.
- It is recommended to wear gloves. …
- Wipe the outside of the containers flasks plates and dishes with 70% ethanol before placing them in the cell culture hood.
- Avoid pouring media and reagents directly from bottles or flasks.
What characteristics of bacteria fungi are observable by exposing?
why are plates labeled on the bottom of the agar plate? what characterics of bacteria/fungi are observable by exposing incubating and examining the growth on agar plates? When plated on culture media samples from most environments will reveal microbial growth.
Are you able to determine the purity of a culture by looking at growth in a broth tube?
You can determine if a broth culture is pure ( all one species of bacteria) by visually inspecting without a microscope. It is not harmful to the bacteria to use a loop that hasn’t been cooled.
What are the basic concepts and precautions observed in specimen collection for microbiological examination?
Specimens should be in tightly sealed leak proof containers and transported in sealable leak-proof plastic bags. Specimens for TB should be double bagged. Specimens should not be externally contaminated. Specimens grossly contaminated or compromised may be rejected.
How would you expect both positive and negative results to be affected if you were to add glucose to the medium?
What is the starch hydrolysis amylase test? … How would you expect both positive and negative results to be affected if you were to add glucose to the medium in the starch hydrolysis test? The glucose would cause the starch breakdown to be slower resulting in a false negativ. What is the DNA Hydrolysis DNase test?
What precautions need to observe in order to maintain safety in the preparation of culture media?
Care should be taken to avoid contact with skin eyes or mucous membranes when handling culture media or any laboratory reagent stain fixative or chemical. If contact occurs flush immediately with running water. Contact a physician hospital or poison control center if overexposure or irritation exists.
PLANT VS ANIMAL CELLS
Observations During the Study of Hair Cell Mechanotransduction
Prokaryotic vs. Eukaryotic Cells (Updated)
Bernal Seminar Series Presenter Dr Marco Franzoni