Life Sciences
GATE XL year:2025 PYQs
Build your understanding with focused practice from past exam papers.
Questions 81–90 of 122. Imported answers require independent review unless marked reviewed.
Question 81
Open questionXL-SMSQ2 marksNeeds review
Which of the following reactions is/are catalyzed by aldolase?
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Open questionXL-SMSQ2 marksNeeds review
Which option(s) correctly match(es) the Antibiotic with their corresponding Target?
Antibiotic | Target |
|---|---|
P. Penicillin | i. Ribosome |
Q. Kanamycin | ii. RNA polymerase |
R. Rifampin | iii. DNA gyrase |
S. Nalidixic acid | iv. Transpeptidase |
T. Ciprofloxacin | |
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 83
Open questionXL-SNAT2 marksNeeds review
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 × 10⁷ E. coli cells.
Assuming normal division, the E. coli culture will lyse completely by _____ full cycles of bacterial division.
(Answer in integer)
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Open questionXL-SNAT2 marksNeeds review
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)
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Open questionXL-TMCQ1 markNeeds review
Which one of the following is a “brood parasite” ?
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During the development of a mammalian embryo, “yolk sac” is formed by which one of the following?
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The animals belonging to which one of the following phyla are characterized by “segmented body” ?
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Which one of the following is a “post-zygotic” isolating mechanism of speciation?
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Desmosomes are
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Open questionXL-TMCQ1 markNeeds review
The “foramen of Panza” is found in which one of the following groups of animals?
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