GATE Overflow for GATE BT - Recent questions and answers in Recombinant DNA Technology

GATE BT 2026 | Question: 16

Mon, 23 Feb 2026 14:21:50 +0000

Which component of the $\text{CRISPR/Cas9}$ gene editing system is $\text{NOT}$ of natural origin?

$\text{CAS9}$ protein
$\text{CRISPR}$ repeats
$\text{PAM}$ sequence
$\text{sgRNA}$

Answered: If 1000 bp of a double-helical DNA weighs 18 1 10−  gm and distance between two bp is0.34nm, the total amount of DNA (in mg, rounded off to one decimal place) required to stretch from Earth to Moon (assuming the distance between Earth and Moon to be 3,74,000 km) is ___________.

Mon, 19 Jan 2026 05:29:43 +0000

1.98mg ~ 2mg

GATE BT 2025 | Question: 10

Thu, 06 Mar 2025 17:05:58 +0000

Which one of the following hosts is used in mammalian cell culture for the production of glycosylated recombinant therapeutic proteins?

Pichia pastoris
Sf$9$ cells
Escherichia coli
Chinese hamster ovary cells

GATE BT 2023 | Question: 35

Sun, 21 May 2023 02:58:25 +0000

Which of the following vector(s) is(are) used to clone a DNA fragment of size $220 \mathrm{~kb}$?

Bacterial artificial chromosome
Yeast artificial chromosome
Cosmids
$\text{pUC19}$ plasmid

GATE BT 2022 | Question: 43

Sun, 20 Mar 2022 16:16:26 +0000

Introduction of foreign genes into plant cells can be carried out using

Agrobacterium
$\text{Cacl}_{2}$ mediated plasmid uptake
Electroporation
Gene gun

GATE2020: 37

Tue, 03 Nov 2020 11:16:26 +0000

The schematic of a plasmid with a gap in one of the strands is shown below:

Which of the following enzyme(s) is/are required to fill the gap and generate a covalently closed circular plasmid?

$DNA$ ligase
AIkaline phosphatase
$DNA$ polymerase
Polynucleotide kinase

$P$ only
$P, R$ and $S$ only
$P$ and $R$ only
$P, Q$ and $R$ only

GATE2020: 42

Tue, 03 Nov 2020 11:14:30 +0000

Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].

Assertion [$a$]: A genetically engineered rice that produces beta-carotene in the rice grain is called Golden rice

Reason [$r$]: Enabling biosynthesis of provitamin $$A in the rice endosperm gives a characteristic yellow/orange color

Both [$a$] and [$r$] are false
Both [$a$] and [$r$] are true but [$r$] is not the correct reason for [$a$]
Both [$a$] and [$r$] are true and [$r$] is the correct reason for [$a$]
[$a$] is true but [$r$] is false

GATE2020: 9

Tue, 03 Nov 2020 11:02:14 +0000

During a positive-negative selection process, transformed animal cells expressing __________________ are killed in presence of ganciclovir in the medium.

Pyruvate kinase
viral thymidine kinase
viral serine/threonine kinase
viral tyrosine kinase

GATE2016-30

Mon, 26 Mar 2018 16:59:49 +0000

Select the CORRECT combination of genetic components that are essential for the transfer of T-DNA segment from Agrobacterium tumefaciens to plant cells.

Border repeat sequences and oncogenes
Border repeat sequences and vir genes
Opine biosynthetic genes and vir genes
Opine biosynthetic genes and oncogenes

GATE2016-36

Mon, 26 Mar 2018 16:59:48 +0000

A $1.2$ kb DNA fragment was cloned into $\textit{Bam}$HI and $\textit{Eco}$RI sites located on a $2.8$ kb cloning vector. The $\textit{Bam}$HI and $\textit{Eco}$RI sites are adjacent to each other on the vector backbone. The vector contains an $\textit{XhoI}$ site located $300$ bp upstream of the $\textit{Bam}$HI site. An internal $\textit{XhoI}$ site is present in the gene sequence as shown in the figure. The resultant recombinant plasmid is digested with $\textit{Eco}$RI and $\textit{Xhol}$ and analyzed through $1 \%$ agarose gel electrophoresis. Assuming complete digestion with $\textit{Eco}$RI and $\textit{Xhol}$, the DNA fragments (in base pairs) visible on the agarose gel will correspond to:

$2800$, $700$ and $500$
$2800$, $700$ and $800$
$2500$, $700$ and $800$
$2500$, $1200$ and $300$

GATE BT 2017 | Question: 42

Mon, 26 Mar 2018 16:43:16 +0000

A recombinant protein is to be expressed under the control of the lac promoter and operator in a strain $\textit{E.coli}$ having the genotype lacI$^+$ crp$^+$ . Even in the absence of inducer IPTG, low levels of expression of the recombinant protein are seen (leaky expression). Which one of the following should be done to minimize such leaky expression?

Addition of lactose to the medium
Removal of all glucose from the medium
Addition of excess glucose to the medium
Addition of allo-lactose to the medium

GATE BT 2017 | Question: 43

Mon, 26 Mar 2018 16:43:16 +0000

Shown below id a plasmid vector (P) and an insert (Q). The insert was cloned into the BamHI site of the vector. The recombinant plasmid was isolated and digested with BamHi or XhoI. The results from the digestion experiments are shown in (R)

Which one of the following explains the digestion results shown in (R)

The insert did not ligate to the vector.
One copy of the insert ligated to the vector.
The insert ligated to the Vector as two tandem copies
The insert ligated to the vector as two copies but not in tandem

GATE BT 2015 | Question: 13

Mon, 26 Mar 2018 15:10:50 +0000

Which one of the following is a second generation genetically engineered crop?

Bt brinjal
Roundup soyabean
Golden rice
Bt rice

GATE BT 2015 | Question: 23

Mon, 26 Mar 2018 15:10:48 +0000

Which one of the following features is NOT required in a prokaryotic expression vector?

$\textit{oriC}$
Selection marker
CMV promoter
Ribosome binding site

GATE BT 2012 | Question: 2

Sun, 25 Mar 2018 08:38:41 +0000

The basis for blue-white screening with $pUC$ vectors is

intraallelic complementation
intergenic complementation
intragenic suppression
extragenic suppression