Question

In: Biology

Which of the following is FALSE regarding Bacterial Endotoxins? a. They can cause Fever and Hemorrhagic...

Which of the following is FALSE regarding Bacterial Endotoxins?

a.

They can cause Fever and Hemorrhagic Shock

b.

They are secreted by the cell

c.

Examples of bacteria that produce them include Clostridium tetani and Bacillus anthracis.

d.

The bacteria are typically found in soil

Which of the following is true regarding Gram (+) and a Gram (-) bacteria?

a.

The Gram (-) have a thick layer of peptidoglycan on the surface of the cell

b.

The Gram (+) have a cell wall and Gram (-) do not have a cell wall

c.

The Gram (+) have a peptidoglycan layer that is sandwiched with a layer of liposaccharides on the surface

d.

The Gram (+) have a thick layer of peptidoglycan on the surface of the cell

Solutions

Expert Solution

1. Bacterial endotoxins : Endotoxins are toxins released by bacteria. Endotoxins are also called Lipopolysaccharide (LPS) are derived from outer membrane of Gram negative bacteria. Lipid component Lipid A of Lipopolysaccharide is associated with toxicity of endotoxins. Endotoxins are heat stable and liberated only on cell lysis or death of bacteria.

The endotoxins are pyrogens, the pyrogens are fever inducing substances produced by bacteria. Endotoxins released from bacteria initiate host inflammatory response. It leads to increased cellular immune response. The inflammatory response is mediated by interleukin, cytokines, tumor necrosis factors, etc. The endotoxins may enter to blood and causes fever, nausea and aseptic shock.

Endotoxins are present almost everywhere in environment. In humans mostly present in digestive system.

Escherichia coli, Klebsiella, Proteus, Pseudomonas, Shigella are some enterotoxin producing bacteria.

False statement is 'c' Examples of bacteria that produce endotoxins are Clostridium tetani and Bacillus anthracis. Both theses are exotoxin producing bacteria.

2. The bacterial species are distnigushed into two main groups based on its cell wall structure and composition as Gram Positive and Gram negative bacteria by Gram staining.

The main distinguishing feature is the thickness of peptidoglycan and presence or absence of outer lipid layer. Gram positive bacteria have thick peptidoglycan layer but lack an outer lipid layer while Gram negative bacteria have a thin peptidoglycan layer covered with a outer lipid layer.

The thick peptidoglycan layer of Gram positive bacteria retain the primary crystal violet during staining and prevent from decolorisation. So cell appears in purple color. But in gram negative bacteria due to thin peptidoglycan layer primary stain crystal violet is decolourised by ethanol and take-up the color of counter stain Safranin and appears red.

Both Gram positive and Gram negative bacteria have cell wall. Gram positive bacteria is single layered while gram negative have double layered cell wall.

d. The Gram (+) have thick peptidoglycan layer on the surface of cell. Is only true statement.


Related Solutions

Which of the following are false regarding financial instruments and money a) Financial instruments can function...
Which of the following are false regarding financial instruments and money a) Financial instruments can function as a means of payment and a store of value b) Money can function as a means of payment and a store of value c) Financial instruments allow for the transfer of risk between buyer and seller. d) Money allows for the transfer of risk between buyer and seller.
Which of the following statements is false regarding a general partnership?
Which of the following statements is false regarding a general partnership?A.It is easy to create.B.Income of the business is personal income.C.Business losses can be deducted from taxes.D.The partners are considered agents of the partnership.E.In most cases partners do not have personal liability for losses.
Artemisinin would be a successful treatment for: cat-scratch disease malaria gram-negative sepsis ebola hemorrhagic fever Which...
Artemisinin would be a successful treatment for: cat-scratch disease malaria gram-negative sepsis ebola hemorrhagic fever Which of the following is caused by a helminth? anthrax yellow fever schistosomiasis toxoplasmosis Sydenham's chorea and subcutaneous nodules are notable symptoms of: rheumatic fever pneumonic plague infectious mononucleosis Chagas' disease Match the following diseases with its corresponding characteristic. Toxoplasmosis Tularemia Yellow fever Brucellosis Lyme disease Hantavirus pulmonary syndrome A. transmitted via contact with cat feces B. transmitted through contact with infected animals or insect...
Which of the following statements is false regarding credit risk analysis?
Which of the following statements is false regarding credit risk analysis?Multiple ChoiceA lender is protected against credit risks by a loan’s covenant provisions since the interest rate is fixed by the Federal Reserve Bank.High-quality financial statements help a credit analyst to see the true performance at a company.Greater default risk is determined to exist when there is significant organizational reliance on a certain individual or customer.An estimate of a firm’s future financial condition is very important to most lending decisions.
Which of the following is false regarding the impact of IT on the audit process? Auditors...
Which of the following is false regarding the impact of IT on the audit process? Auditors should evaluate the effectiveness of application controls before evaluating general controls. Because auditors are responsible for obtaining an understanding of internal control, they must be knowledgeable about general and application controls, whether the client’s use of IT is simple or complex. The systematic nature of automated application controls may allow auditors to reduce sample sizes used to test those controls in both an audit...
Regarding normal aging, which of these statements is FALSE? Amyloid plaques can be seen in the...
Regarding normal aging, which of these statements is FALSE? Amyloid plaques can be seen in the brain of healthy seniors (normal aging). Ageism is a form of age discrimination that can affect both the elderly and the young. Compared to young people, the brain of the elderly person generally needs less neural resources to accomplish a similar task. The brain volume decreases by about 2% per decade during adulthood to older age. Anatomical changes in the brain during aging are...
Which of the following is most FALSE regarding the geneticsubstrate (variation) on which selection acts?...
Which of the following is most FALSE regarding the genetic substrate (variation) on which selection acts?Group of answer choicesInbreeding, caused by genetic drift, results in a high level of homozygosity in a populationSex creates new combinations of genotypesGenetic drift could reduce the levels of allelic and genotypic variationMutations are a source of allelic variationEpigenetic modifications give rise to allelic diversity
Which of the following statements regarding Lewis dot symbols of ions is false? Which of the...
Which of the following statements regarding Lewis dot symbols of ions is false? Which of the following statements regarding Lewis dot symbols of ions is false? Mg2+ always has one electron around it. In ionic compounds containing chloride, ions, Cl− is isoelectronic with Ar. In magnesium sulfide, S2− has eight electrons. In sodium chloride, Na+ has no electrons around it.
Which of the following is not true regarding reasonable cause for penalty abatement? Reasonable cuase is...
Which of the following is not true regarding reasonable cause for penalty abatement? Reasonable cuase is an inability to meet tax filing a payment resonsibilities fue to circumstances beyond the taxpayer's control. Reasonable reliance on erroneous written advice from the IRS is considered reasonable cause. Reasonable cause is a defense to the estimated tax penalty. Death, serious illness, or unavoldable absence of the taxpayer may constitute reasonable cause.
Water is an unique substance. Which of the following is false regarding water ? (a) many...
Water is an unique substance. Which of the following is false regarding water ? (a) many ionic salts dissolve well in water due to the ions’ tendency to H-bond with the water (b) each water molecule engages in four H-bonds with its neighboring water molecules (c) water’s H-bonding capability results in water’s exceptionally high heat of vaporization (d) the density of ice is less than that of liquid water due to the hexagonal, open structure of ice (e) water has...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT