In the Messelsohn-Stahl experiment, there should be ______ band(s) in the centrifugation tube after two generations of bacterial growth in normal nitrogen. Group of answer choices None of these One light and one medium density Two light and heavy Three light bands One heavy
Q: Calculate the percentage efficiency of extraction of phycocyanin in sample 3, if the amount of…
A: Given Values: Amount of phycocyanin in sample = 119.2 mg Amount of phycocyanin extracted from sample…
Q: When testing the sensitivity of antibiotics using the Kirby-Bauer method, the Petri Dish with…
A: The Kirby-Bauer test, known as the disk-diffusion method, is the most widely used antibiotic…
Q: Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli…
A: UV radiations are known to cause genetic damage and cessation of bacterial growth. UV-irradiation is…
Q: Which of the following tools cannot facilitate the visualization of specific intracellular proteins…
A: Radio isotopes can visualise uptake and downtake but not specific intra cellular proteins. DNA…
Q: Nitrogen fixing bacteria can use atmospheric nitrogen as their sole source of nitrogen. Imagine you…
A: The microbes are grown in an artificial culture medium in a laboratory set up. These media provide…
Q: Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli…
A: Conceptual Introduction UV radiations are known to cause genetic damage and cessation of bacterial…
Q: Erwin Chargaff did not have any DNA samples from thermoacidophilic bacteria such as those that…
A: Nucleic acids, DNA, and RNA are composed of nucleotides. Each nucleotide is composed of a…
Q: You measure your E. coli and find them to have an OD600 of 1.20. You have 50 ml of culture, and you…
A: The growth curve of a bacterial culture can be assessed by measuring its optical density at 600 nm…
Q: Which of these given statements is inaccurate about bacterial endospores? Question 12…
A: Endospores are the dormant form of bacteria which allow bacteria to resist the harsh environment. In…
Q: In the experiment performed by Messelson and Stahl, bacterial cells grown in 1N-containing growth…
A: Watson and Crick proposed the semi-conservative model for the replication of DNA. Later, this was…
Q: If a bacterial species is not susceptible to an antibacterial drug at the concentration present in a…
A: Antibiotic susceptibility test is the test used to determine the effect of antibiotic to an…
Q: Three different strains of Escherichia coli, respectively A, B, and C have been inoculated in three…
A: E.coli cells take around 20 mins to replicate themselves. The replication of bacteria is an…
Q: f you compare the standards on bacteria provided by the simulation, a higher level is acceptable for…
A: Concept used: Industrial and recreational waters' water quality. Important terms: Water for…
Q: A population of E. coli is grown in a glucose medium and transferred daily into a fresh medium when…
A: The population has reached the carrying capacity.
Q: Which of the following is used extensively in biochemical and genetic work ? (a) Agaricus (b)…
A: All the organisms given in the question are different types of fungi. Organisms belonging to the…
Q: The following is the PCR reaction that is programmed in the thermocycler to amplify the cheek cell…
A: Polymerase chain reaction (PCR) is a method that is used to amplify a selected region of DNA and…
Q: A growth medium consisting of only known amounts of water, magnesium, calcium chloride, potassium…
A: The growth medium, also called as Nutrient Broth, is a kind of solution which is sterilized to get a…
Q: For a bacterium that prefers a neutral pH and has an optimal (best) growth pH of 7, how would growth…
A: The optimum pH for the growth of microbes is the favorable pH for that organism. The lowest pH value…
Q: Which of the following agents if introduced into a growing culture of bacteria would halt growth but…
A: INTRODUCTION Bacteria, also called germs, are microscopic organisms not visible with the naked eye.…
Q: a. Let’s say for example that a milk sample has 10,000 bacteria per milliliters. If 1 mL of this…
A: A serial dilution is a process of sequential dilution in order to decrease the density of cell…
Q: In the experiment by Bernard Davis, bacterial F+cells and F- cells were growing while separated by a…
A: The transfer of genetic material between bacteria can occur in three different ways, Conjugation,…
Q: Besides being able to tolerate a range of pH some bacteria change their environment by producing…
A: Due to metabolic activities of the bacteria/microbes, different bye-products are produced which…
Q: If you were to analyze three separate colonies from the plate above, would you expect them all to be…
A: Microbes, which are tiny and nearly invisible, have had a huge influence on society since the…
Q: You use a spectrophometer and estimate the concentration of bacteria in a urine sample to be 4.6 x…
A: dilution factor =10^-6
Q: Your unknown sample will contain two different bacterial species. The same biochemical tests…
A: Different types of bacterial species present in sample require different biochemical tests.
Q: Fifteen bacterial colonies growing on a complete medium (that means that they have all of nutrients…
A: Bacteria are capable of synthesizing all the 20 amino acids. In a complete medium, all the nutrients…
Q: You are working with an intestinal bacterium of humans, which you have in pure culture (in liquid…
A: Microbiology is the branch of biology that deals with study of organisms that are too small to be…
Q: Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli…
A: UV light at 254 nanometers is used as a sterilization method in medical environments, labs,…
Q: Escherichia coli but not Pyrolobus fumarii will grow at 40°C, while P. fumarii but not E. coli will…
A: Microbes are classified based on the adapted environment. There are mesophiles, thermophiles and…
Q: Suppose 1,000 bacteria are inoculated into a tube of a minimal salt medium where they double once an…
A: Minimal medium is a medium that contains minimal necessities for the microbe to grow. A nutrient…
Q: After a sufficient incubation period, bacterial growth occurred except in the zones of inhibition…
A: Antibiotics can be defined as a chemical compound ; generally releases by the microorganisms ; that…
Q: In theory, if a 1-liter culture of rich medium is inoculated with 3 bacterial cells per milliliter,…
A: Generation time is the time taken for the doubling of the single cell. According to data given in…
Q: Strain X. spp. is a rod-shaped, anaerobic, Gram-positive bacterium with peritrichous flagella and…
A: Given information Doubling time 240 minutes = 4 hours. Initial population = 10 cells Final…
Q: Compare and contrast bacteriocidal, bacteriostatic and bacteriolytic agents. What are their effects…
A: It is critical that we understand microbes and their applications since they may be both useful and…
Q: Which form of the Coomassie dye do you expect to be more prevalent in a low pH solution? Group of…
A: Coomassie dye binds to proteins through ionic interactions between sulfonic acid groups and…
Q: Strain X. spp. is a rod-shaped, anaerobic, Gram-positive bacterium with peritrichous flagella and…
A: Doubling time is the time required by a cell, in this case the bacterial cell, to divide and produce…
Q: Which of the answers below represents the correct mathematical expression of bacterial growth of…
A: The formula for bacterial growth is as follows: Nt = No × 2n Where Nt= bacterial population at time…
Q: In the experiment performed by Messelson and Stahl, bacterial cells grown in 15N-containing growth…
A: It is majorly present within the nucleus. DNA can exist in different levels of complexity. Primary…
Q: In a series of infection experiments, a researcher discovers that the ID50 value for the infectious…
A: Answer Parasiticum mucoides
Q: The following is the PCR reaction that is programmed in the thermocycler to amplify the cheek cell…
A: PCR ( polymerase chain reaction ) is a technique in which numerous copies of DNA are synthesized .…
Q: In a series of infection experiments, a researcher discovers that the ID50 value for the infectious…
A: A pathogen is a microorganism that can be a bacteria, virus, protozoan, etc. which has the…
Q: Which of the following statements describe a culture or molecular technique in the study of…
A: All statements are acceptable in describing a molecular technique or culture in the study of…
Q: In a biological production process, bacteria with spore-forming ability are immobilized on a support…
A: Introduction :- Spore-forming bacteria are more resilient than most minuscule unicellular organisms.…
Q: Use the following diagram to answers the questions. A. Is this cell Gram + or Gram -? Provide 2…
A: Bacteria are a broad collection of tiny, unicellular creatures that have been classed as prokaryotic…
Q: How long does it take for E. coli to go from lag phase at time 0 to log phase to stationary phase to…
A: The unicellular organisms divide into two and so on replicating the genetic material as well as…
Q: When the number of colony-forming units per milliliter is calculated, you will focus your counts on…
A: A Petri dish (also known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish…
Q: A 0.00001 dilution is performed on a culture of bacteria in order to perform viable plate counts.…
A: When the culture medium is dispersed on the viable plate, a very thin layer is formed in which…
Q: Describe how you would make 10 ml of a 1:500 dilution of bacteria by performing TWO SEPARATE…
A: A serial dilution is the stepwise dilution of a substance in solution. Normally the dilution factor…
Q: You are studying a type of bacteria isolated from the acidic water runoff of a mining operation. You…
A: INTRODUCTION In chemistry, pH traditionally denoting "ability of hydrogen" is a scale used to…
Q: Suppose you have a bacterium, which is normally killed in an hour when growing in a medium…
A: It is given that the given bacterium is the auxotrophic and requires the tryptophan for its growth…
Gene Interactions
When the expression of a single trait is influenced by two or more different non-allelic genes, it is termed as genetic interaction. According to Mendel's law of inheritance, each gene functions in its own way and does not depend on the function of another gene, i.e., a single gene controls each of seven characteristics considered, but the complex contribution of many different genes determine many traits of an organism.
Gene Expression
Gene expression is a process by which the instructions present in deoxyribonucleic acid (DNA) are converted into useful molecules such as proteins, and functional messenger ribonucleic (mRNA) molecules in the case of non-protein-coding genes.
In the Messelsohn-Stahl experiment, there should be ______ band(s) in the centrifugation tube after two generations of bacterial growth in normal nitrogen.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
- Which of the following samples are expected to cause a decrease in absorbance over time when performing light scattering experiments with bacteria? HEW, CARB 1 and Lysozyme standards Lysozyme standards and CARB 1 Lysozyme standards HEW, LOAD, and CARB1 You take 0.5 mL of Carb 1 and add it to 2.0 mL of buffer. You then add 7.5 mL Biuret to this sample. The total dilution of Carb 1 in the final sample is 9 20 10 0.05Imagine you have been given a liquid culture of yeast with a starting concentration of 3.67 x 10' cells/ml and are asked to carry out the sample dilution process shown in the figure below. 100μl 100μl 100μl 100μl 100μl 0.9ml 0.9ml 0.9ml H2O H₂O 6.9ml 0.9ml H₂O H₂O H₂O Original 10-1 102 10-3 104 Culture 105 100μl 100μl 100μl Plate A Plate B Plate C a. How many colonies should have been present on Plate A in this example? - Answers must be whole numbers as partial colonies are not expected. b. Imagine you carried out the same dilution scheme shown in the figure above, but now, you do not know the concentration of the original culture. If you counted 163 colonies on Plate B, what is the concentration of cells/ml in the original culture?SEPARATION OF COMPONENTS BY CENTRIFUGATION Consider the following subcellular components and their corresponding sedimentation rates. Table 3. Sedimentation rates of four subcellular components for isolation. CENTRIFUGAL FORCE (xg) SUBCELLULAR COMPONENT CDCP 14896 AJRA 967 AGC 382 JCKSP 2378 Two centrifuge machines are available in your laboratory. Centrifuge A has a rotor diameter of 14 cm and a maximum speed of 3500 rpm while centrifuge B has a rotor diameter of 18 cm and a maximum speed of 14500 rpm. Construct a separation scheme of the four subcellular components considering the following parameters: The four components are separated into pellet/supernatant I and pellet/supernatant II. Only two centrifugation steps are performed; specify the centrifugal speeds (in rpm) per step. Show relevant calculations. Both centrifuge machines must be used in the procedure. Components of each fraction are indicated.
- In growing E.coli, why is that (reasons) they do not grow after doubling time under 20 degrees celsius and under 37 degrees celsius, the number of colonies after doubling time has decreased?Bacteria count Shown is a typical graph of the number N of bacteria grown in a batch culture as a function of time 1. Describe what you think is happening during each of the four phases. NAThe colony forming units (CFU)/ml in sauerkraut brine are given for different types of bacteria except for leuconostoc (shaded column). To obtain the Leuconostoc counts for different days, 40 microlitre of sauerkraut brine was 10-fold diluted and the CFU was determined by plating different dilutions on agar plates. For Day 0 56 CFU were counted in 10-1 dilution, Day 1 81 CFU were counted in 10-3 dilution, Day 2 86 CFU were counted in 10-3 dilution Day 5 78 CFU were counted in 10-5 dilution Calculate the CFU/ml of leuconostoc in the brine for the 4 different days. Show your calculation
- Bacteria grow in a nutrient solution at a rate proportional to the amount present. Initially, there are 250strands of the bacteria in the solution which grows to 800 strands after seven hours. Show (a) anexpression for the approximate number of strands in the culture at any time t and (b) the time needed forthe bacteria to grow to 1600 strands.How many colonies would you expect to count at each 5-fold dilution (5-1 until 5-6), when you have 338,000 bacteria present per gram of a meat sample. Given you inoculate 1 mL of each of these dilutions.A bacterial strain has a generation time of 30 min, how long would it take an exponentially growing culture to increase from a titre of 5 x 103 cells per ml to 4 x 109 cells per ml? How many generations would have elapsed? Show all of your calculations. G = t/n to calculate generation time (i.e. for population to double) During the growth of the culture, periodic observations of the cells under the microscope have revealed the occurrence of typical rod-shaped cells. However, after further incubation, they appeared to change their morphology to form small oval or spherical-shaped structures. What do these structures likely represent? And what are the likely factors contributing to this observation? Explain what growth phase this culture will be in.
- Two flasks of E. coli are grown in batch culture in the same medium (2% glucose and amino acids; no nitrate) and at the same temperature (378C). Culture #1 is well aerated. Culture #2 is anoxic. After 16 hours the following observations are made: ■ Culture #1 has a high cell density; the cells appear to be in stationary phase, and the glucose level in the medium is reduced to 1.2%. ■ Culture #2 has a low cell density; the cells appear to be in logarithmic phase, although their doubling time is prolonged (over 1 hour). The glucose level is reduced to 0.2%. Why does culture #2 have so little glucose remaining relative to culture #1, even though culture #2 displayed slower growth and has less biomass?Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli after incubation. Which side of the plate do you think has a 'zero-minute' negative control? A or B or neither? Explain with proper reasoning. Egli Eoli ky 9.In growing E.coli, why is that (reasons) they do not grow after doubling time under 20 degrees celsius and under 37 degrees celsius, the number of colonies after doubling time has decreased? provide reliable sources (links).