Biotechnology
GATE BT year:2025 PYQs
Build your understanding with focused practice from past exam papers.
Questions 31–40 of 65. Imported answers require independent review unless marked reviewed.
Question 31
Open questionBTNAT1 markNeeds review
The contour length of a B-DNA molecule that encodes a bacterial protein of 33 kDa is _____ nm.
Consider the average molecular weight of an amino acid as 110 Da and helix rise per base pair for B-DNA as 0.34 nm.
(Round off to the nearest integer)
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Within the Michaelis-Menten framework, the ratio of
when
is _____ .(Round off to two decimal places)
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Consider a nonlinear algebraic equation,
. Using the Newton-Raphson method, with the initial guess of
, the approximated value of the root of the equation after one iteration is _____ .(Round off to two decimal places)
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The value of
, for which the linear equations
and
have at least one solution, is ____________.(Answer in integer)
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Two fair six-sided dice, with sides numbered 1 to 6, are thrown once. The probability of getting 7 as the sum of the numbers on the top side of the dice is ______________.
(Round off to two decimal places)
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Open questionBTMCQ2 marksNeeds review
Correctly match the Microorganisms with their respective Nutrition and energy requirement.
Microorganisms | Nutrition and energy requirement |
|---|---|
P. Photoautotrophs | 1. Use organic compounds as a source of energy, hydrogen, electron and carbon |
Q. Chemoorganotrophs | 2. Use light energy and use CO₂ as their carbon source |
R. Chemolithoautotrophs | 3. Use light energy and use organic compounds as electron donor and carbon source |
S. Photoorganoheterotrophs | 4. Oxidise reduced-inorganic molecules as energy and electron source but derive carbon from organic sources |
Your answerChoose one option.
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Correctly match the Inhibitor with its respective Function in mitochondrial respiration.
Inhibitor | Function |
|---|---|
P. FCCP | 1. Inhibits cytochrome c oxidase |
Q. Cyanide | 2. Makes the membrane permeable to protons |
R. Oligomycin A | 3. Blocks mitochondrial uptake of succinate |
S. Butyl malonate | 4. Inhibits ATP synthase |
Your answerChoose one option.
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An octapeptide composed of these L-amino acids — Lys, Thr, Ser, Met, Arg, Trp, Tyr, Glu — was subjected to analyses with the following outcomes:
P. The N-terminal sequencing analysis by Sanger’s method yielded ‘Ser’ at the N-terminus
Q. Chymotrypsin treatment gave a pentapeptide, a ‘Tyr’ containing dipeptide and a free ‘Glu’
R. Cyanogen bromide treatment gave two tetrapeptides
S. Trypsin treatment gave two tripeptides and a dipeptide
Which one of the following is the correct octapeptide sequence?
Your answerChoose one option.
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Correctly match the type of Hypersensitivity reaction with its respective Example.
| Hypersensitivity reaction | Example |
| P. Type I | 1. Tuberculin reaction |
| Q. Type II | 2. Arthus reaction |
| R. Type III | 3. Chronic urticaria |
| S. Type IV | 4. Systemic anaphylaxis |
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Open questionBTMCQ2 marksNeeds review
Correctly match the Enzyme with its respective Function.
| Enzyme | Function |
| P. Gyrase | 1. Removes a damaged base by cleaving the bond between sugar and base |
| Q. Deadenylase | 2. Provides a swivel allowing one DNA strand to rotate around the other |
| R. Glycosylase | 3. Catalyses bond formation between 3′-OH and 5′-phosphate end of nucleotides in duplex DNA |
| S. DNA ligase | 4. Is an exonuclease that removes the poly(A) tail |
Your answerChoose one option.
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