The adaptive immune response in an animal involves the generation of antibodies against an invading bacterial pathogen. The following graph represents antibody titer levels in a mammal exposed twice to the pathogen.
Which one of the following options correctly pairs antibodies to peak I and peak II in the graph?
The adaptive immune response in an animal involves the generation of antibodies against an invading bacterial pathogen. The following graph represents antibody titer levels in a mammal exposed twice to the pathogen.
Which one of the following options correctly pairs antibodies to peak I and peak II in the graph?
Show Hint
- Peak I - IgG; Peak II - IgM
- Peak I - IgM; Peak II - IgG
- Peak I - IgE; Peak II - IgG
- Peak I - IgG; Peak II - IgG
The Correct Option is B
Solution and Explanation
- Peak I corresponds to the primary response, which is characterized by the production of IgM antibodies first. This is the body's initial response to the pathogen.
- Peak II corresponds to the secondary response (after the second exposure), where the production of IgG antibodies predominates. This response is more rapid and robust compared to the primary response due to memory cells.
Thus, the correct pairing of antibodies to the peaks is:
- Peak I - IgM (first exposure)
- Peak II - IgG (second exposure)
Therefore, the correct answer is (B) Peak I - IgM; Peak II - IgG.
Top Questions on Bacterial cell
- A polymerase chain reaction (PCR) based diagnosis test was performed on a bacterial sample targeting a specific gene. There are 3 copies of this gene in the bacterial genome. Prior to DNA extraction, the bacteria were incubated to allow one cycle of growth. 3072 amplicon copies were obtained after 9 cycles of the PCR. Assume 100% efficiency at each step. The initial bacterial count in the sample was ....... (Answer in integer)
- GATE XL - 2025
- Microbiology
- Bacterial cell
- The doubling time of {Escherichia coli is 30 minutes in a culture medium containing glucose and yeast extract. Phage T7 has a life cycle of 20 minutes and a burst size of 200 phage per infected {E. coli} cell. Phage absorption is instantaneous and occurs at 1 multiplicity of infection (MOI). Bacteria infected with multiple or single phage give the same burst. 5000 plaque forming units of T7 phage are added to a culture of \( 2 \times 10^7 \) {E. coli} cells. Assuming normal division, the {E. coli} culture will lyse completely by ........ full cycles of bacterial division. (Answer in integer)}
- GATE XL - 2025
- Microbiology
- Bacterial cell
The doubling time of Escherichia coli is 30 minutes in a culture medium containing glucose and yeast extract. Phage T7 has a life cycle of 20 minutes and a burst size of 200 phage per infected E. coli cell. Phage absorption is instantaneous and occurs at 1 multiplicity of infection (MOI). Bacteria infected with multiple or single phage give the same burst. 5000 plaque forming units of T7 phage are added to a culture of \( 2 \times 10^7 \) E. coli cells. Assuming normal division, the E. coli culture will lyse completely by ........ full cycles of bacterial division. (Answer in integer)}
- GATE XL - 2025
- Microbiology
- Bacterial cell
Which option(s) correctly match(es) the structures in a bacterial cell (Column I) with their corresponding functions (Column II)?
- GATE XL - 2025
- Microbiology
- Bacterial cell
A penicillin sensitive Escherichia coli population is exposed to a lethal dose (200 µg/ml) of penicillin. Assuming density-independent mortality, which one of the following relationships would describe the number of surviving bacteria (N) over time (T)?
- GATE XL - 2025
- Microbiology
- Bacterial cell
Questions Asked in GATE XL exam
- Imagine a population of diploid species in Hardy-Weinberg equilibrium. The population has two alleles for a gene which are ‘a’ and ‘A’. The number of individuals with ‘aa’ genotype in this population is 1 in 10000. The frequency of the allele ‘A’ in the population is ............ (up to two decimal places)
- GATE XL - 2025
- Zoology
- The \( F_{121} \) value of a known microorganism with \( Z \) value of \( 11^\circ C \) is 2.4 min for 99.9999% inactivation. For a 12D inactivation of the said microorganism at \( 143^\circ C \), the \( F \) value (in min) is .......... {(rounded off to 3 decimal places)}
- GATE XL - 2025
- Food Technology
- In a typical grinding operation, 80% of the feed material passes through a sieve opening of 4.75 mm; whereas, 80% of the ground product passes through 0.5 mm opening. If the power required to grind 2 tonnes/h of the feed material is 3.8 kW, the work index of the material is ........ (rounded off to 2 decimal places)
- GATE XL - 2025
- Food Technology
- The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ......... (rounded off to 2 decimal places).
- GATE XL - 2025
- Food Technology
- An enzyme, which follows Michaelis-Menten equation, catalyzes the reaction A\(\rightarrow\)B. When enzyme and substrate concentrations are 15 nM and 10 \(\mu\)M, respectively, the reaction velocity is 5 \(\mu\)M s\(^{-1}\). If \(K_m\) for the substrate A is 5 \(\mu\)M, the kinetic efficiency of the enzyme will be ______ \(\times 10^6\) M\(^{-1}\) s\(^{-1}\) (in integer).
- GATE XL - 2025
- Zoology