GATE Overflow for GATE BT - Recent questions and answers in Plants

GATE BT 2026 | Question: 15

Mon, 23 Feb 2026 14:21:52 +0000

Which one of the following options represents the products of light reactions of photosynthesis in plants?

$\mathrm{O}_{2} / \mathrm{NADH} / \mathrm{H}_{2}$
$\mathrm{O}_{2} / \mathrm{NADP}^{+} / \mathrm{CO}_{2}$
$\mathrm{O}_{2} / \mathrm{NADPH} / \mathrm{ATP}$
$\mathrm{O}_{2} / \mathrm{NADP}^{+} / \mathrm{ATP}$

GATE BT 2025 | Question: 38

Thu, 06 Mar 2025 17:04:57 +0000

Correctly match the herbicide with its mode of development of resistance in plants.
\begin{array}{|l|l|}
\hline \textbf{Herbicide } & \textbf{Mode of development of resistance} \\
\hline \text{P. Imidazolinones} & 1. \text{Transformation of bacterial nitrilase gene} \\
\hline \text{Q. Bromoxynil} & 2. \text{Transformation of resistant version} \\ & \text{of acetolactate synthetase} \\ \hline \text{R. Glufosinate} & 3. \text{Transformation of} \textit{ tfdA } \\ & \text{gene from} \text{ Alcaligenes}, \\ & \text{which encodes a dioxygenase} \\ \hline & 4. \text{Transformation of bar gene from} \text{Streptomyces hygroscopicus } \\ & \text{which encodes phosphinothricin acetyltransferase} \\ \hline \end{array}

$\mathrm{P}-2 ; \mathrm{Q}-1 ; \mathrm{R}-4$
$\mathrm{P}-2 ; \mathrm{Q}-1 ; \mathrm{R}-3$
$\mathrm{P}-1 ; \mathrm{Q}-2 ; \mathrm{R}-3$
$\mathrm{P}-4 ; \mathrm{Q}-1 ; \mathrm{R}-3$

GATE BT 2024 | Question: 35

Mon, 25 Mar 2024 19:16:15 +0000

Which of the following plant-based secondary metabolites belong(s) to the class of alkaloids?

Ajmalicine $\left(\mathrm{C}_{21} \mathrm{H}_{24} \mathrm{~N}_2 \mathrm{O}_3\right)$
Azadirachtin $\left(\mathrm{C}_{35} \mathrm{H}_{44} \mathrm{O}_{16}\right)$
Camptothecin $\left(\mathrm{C}_{20} \mathrm{H}_{16} \mathrm{~N}_2 \mathrm{O}_4\right)$
Vinblastine $\left(\mathrm{C}_{46} \mathrm{H}_{58} \mathrm{~N}_4 \mathrm{O}_9\right)$

GATE BT 2024 | Question: 37

Mon, 25 Mar 2024 19:16:15 +0000

Which of the following is/are considered as biotic elicitor(s) in plant cell culture?

Cellulase
Chitin
Chitosan
Mercuric chloride

GATE BT 2024 | Question: 39

Mon, 25 Mar 2024 19:16:15 +0000

Which of the following is/are synthetic auxin(s) that does/do NOT occur naturally?

$2,4$-Dichlorophenoxyacetic acid
Indole-$3$-acetic acid
Indole-$3$-butyric acid
$1$-Naphthaleneacetic acid

Answered: GATE BT 2023 | Question: 19

Mon, 05 Feb 2024 14:26:24 +0000

Answer A - Auxin

Auxin act as the master mind of rooting. It governs the formation of adventitious roots and also organization of the root.

GATE BT 2023 | Question: 9

Sun, 21 May 2023 02:58:44 +0000

Which one of the following statements is TRUE about leghemoglobin?

It binds oxygen to protect nitrogenase
It binds hemoglobin to protect oxygenase
It binds oxygen to protect hydrogenase
It binds oxygen to protect oxygenase

GATE BT 2023 | Question: 33

Sun, 21 May 2023 02:58:26 +0000

Which of the following is(are) plant protoplast fusogenic agent(s)?

Sodium nitrate
Polyvinyl alcohol
Polyethylene glycol
Bromoxynil

GATE 2022 -BT

Wed, 08 Mar 2023 19:13:28 +0000

The specific growth rate of a mold during exponential phase of its growth in a batch cultivation is 0.15 h−1 . If the cell concentration at 30 h is 33 g L−1 ,

the cell concentration in g L−1 (rounded off to the nearest integer) at 24 h is ________.

GATE BT 2021 | Question: 31

Mon, 01 Mar 2021 03:19:48 +0000

Which of the following combinations of plant hormones and their associated function are $\text{CORRECT}$?

$$\begin{array}{|l|l|l|} \hline & \textbf{Hormone} & \textbf{Function} \\ \hline P. & \text{Abscisic acid} & \text{Breaks seed dormancy} \\ \hline Q. & \text{Auxin} & \text{Induces cell division} \\ \hline R. & \text{Ethylene} & \text{Stimulates ripening of fuits} \\ \hline S. & \text{Gibberellin} & \text{Promotes seed dormancy} \\ \hline \end{array}$$

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

GATE BT 2021 | Question: 35

Mon, 01 Mar 2021 03:19:47 +0000

Which of the following statement(s) is/are $\text{CORRECT}$ about $\textit{Agrobacterium tumefaciens}$?

It contains tumor inducing plasmid
It causes crown gall disease in dicotyledonous plants
It is a Gram-positive soil bacterium
It is used in generating transgenic plants

GATE2019: 44

Tue, 03 Nov 2020 12:02:06 +0000

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

Assertion $[a]$ : It is possible to regenerate a whole plant from a single plant cell.
Reason $[r]$ : It is easier to introduce transgenes in to plants than animals.

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

GATE2020: 32

Tue, 03 Nov 2020 11:16:27 +0000

Some of the cytokinins used in plant tissue culture media are given below:

$BAP$
Zeatin
Kinetin
$2iP$

Which of these are synthetic analogs?

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

GATE2016-31

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

Match the secondary metabolites (Column-I) with the corresponding plant species (Column-II).

$\begin{array}{|l|l|l|l|} \hline & \textbf{Column-I} & &\textbf{Column-II} \\ \hline P. & \text{Morphine} & 1. & \textit{Datura stramonium} \\ \hline Q. & \text{Pyrethrins} & 2. & \textit{Catharanthus roseus} \\ \hline R. & \text{Scopolamine} &3. & \textit{Papaver somniferum} \\ \hline S. & \text{Vincristine} & 4. & \textit{Tagetes erecta} \\ \hline \end{array}$

$\text{P-4, Q-3, R-1, S-2}$
$\text{P-3, Q-4, R-1, S-2}$
$\text{P-2, Q-3, R-4, S-1}$
$\text{P-4: Q-1, R-2, S-3}$

GATE BT 2017 | Question: 11

Mon, 26 Mar 2018 16:43:20 +0000

The plant hormone indole-$3$-acetic acid is derived from

histidine
tyrosine
tryptophan
proline

GATE BT 2017 | Question: 36

Mon, 26 Mar 2018 16:43:17 +0000

Which one of the following organisms is responsible for crown gall disease in plants?

$\textit{Xanthomonas campestris}$
$\textit{Rhizobium etli}$
$\textit{Agrobacterium tume faciens}$
$\textit{Erwinia stewartii}$

GATE BT 2017 | Question: 38

Mon, 26 Mar 2018 16:43:17 +0000

Match the plant hormones in $\textbf{Column I}$ with functions in $\textbf{Column II}$

$\begin{array}{|l|l|l|l|} \hline & \textbf{Column I} && \text{Column II} \\ \hline P. & \text{Gibberellic acid} & 1. & \text{Seed and bud dormancy} \\ \hline Q. & \text{Zeatin} & 2. & \text{Fruit ripening} \\ \hline R. & \text{Ethylene} & 3. & \text{Delaying leaf senescence} \\ \hline S. & \text{Abscisic acid} & 4. & \text{Regulation of plant height} \\ \hline \end{array}$

$\text{P-4, Q-3, R-2, S-1}$
$\text{P-4, Q-2, R-3, S-1}$
$\text{P-3, Q-1, R-2, S-4}$
$\text{P-2, Q-1, R-4, S-3}$

GATE BT 2015 | Question: 49

Mon, 26 Mar 2018 15:10:45 +0000

Choose the CORRECT sequence of steps involved in cytoplast production.

Digestion of cell wall $\to$ protoplast viability $\to$ cybrid formation $\to$ osmotic stabilizer
Osmotic stabilizer $\to$ digestion of cell wall $\to$ protoplast viability $\to$ cybrid formation
Protoplast viability $\to$ osmotic stabilizer $\to$ digestion of cell wall $\to$ cybrid formation
Osmotic stabilizer $\to$ digestion of cell wall $\to$ cybrid formation $\to$ protoplast viability

GATE2014-38

Sun, 25 Mar 2018 23:27:36 +0000

Match the following photoreceptors with their prosthetic groups and spectral specificity:

$\begin{array}{|l|l|l|} \hline \textbf{Photoreceptor} & \textbf{Moiety that absorbs light} & \textbf{Absorption (nm)} \\ \hline \text{P. Phototropin} & \text{1. Chromobilin} & \text{a. }400-500 \\ \hline \text{Q. Cryptochrome} & \text{2. FAD} & \text{b. } 600- 800 \\ \hline \text{R. Phytochrome} & \text{3. FMN} & \text{c. } 500-600 \\ \hline \end{array}$

$\text{P-3-a, Q-2-a, R-1-b}$
$\text{P-1-b, Q-1-a, R-3-b}$
$\text{P-3-a, Q-1-a, R-1-c}$
$\text{P-2-c, Q-1-c, R-1-a}$

GATE2014-39

Sun, 25 Mar 2018 23:27:36 +0000

Match the following plant sources with their secondary metabolites and medical uses:

$\begin{array}{|l|l|l|} \hline \textbf{Source plant} & \textbf{Secondary metabolites} & \textbf{Medical use} \\ \hline \text{P. Belladona} & \text{1. Menthol} & \text{a. Cancer treatment} \\ \hline \text{Q. Foxglove} & \text{2. Atropine} & \text{b. Heart disease} \\ \hline \text{R. Pacific yew} & \text{3. Digitalin} & \text{c. Eye examination} \\ \hline \text{S. Eucalyptus} & \text{4. Taxol} & \text{d. Cough} \\ \hline \end{array}$

$\text{P-2-c, Q-3-b, R-4-a, S-1-d}$
$\text{P-3-c, Q-2-a, R-1-d, S-4-b}$
$\text{P-2-c, Q-4-b, R-1-a, S-3-d}$
$\text{P-1-b, Q-4-c, R-2-d, S-3-a}$

GATE2014-40

Sun, 25 Mar 2018 23:27:36 +0000

The pungency of mustard seeds is primarily due to secondary metabolites such as isothiocyanate and nitrile. The pungency is usually felt only when the seeds are crushed. This is because of

the coat of the intact seeds blocks the pungent volatiles from being released
the pungent chemicals are stored as inactive conjugates and compartmentalized from the enzymes that convert them into active chemicals
the pungent chemicals are formed only after the reaction with atmospheric oxygen
the pungent chemicals are formed only after the reaction with atmospheric carbondioxide

GATE2014-50

Sun, 25 Mar 2018 23:27:35 +0000

If a plant is shifted to cold temperature, which of the following changes would take place in its membrane?

Ratio of unsaturated to saturated fatty acids would increase
Ratio of unsaturated to saturated fatty acids would decrease
Absolute amount of both fatty acids would increase keeping the ratio same
Absolute amount of both fatty acids would remain unchanged

GATE BT 2012 | Question: 36

Sun, 25 Mar 2018 08:38:46 +0000

Determine the correctness or otherwise of the following $Assertion$ (a) and $Reason$ (r).

$Assertion:$ In direct somatic embryogenesis, embryos are developed without going through callus formation.

$Reason:$ This is possible due to the presence of pre-embryonically determined cells.

Both (a) and (r) are true and (r) is not the correct reason for (a)
(a) is false but (r) is true
(a) is true but (r) is false
Both (a) and (r) are true and (r) is the correct reason for (a)

GATE BT 2012 | Question: 35

Sun, 25 Mar 2018 08:38:46 +0000

Determine the correctness or otherwise of the following $Assertion$ (a) and $Reason$ (r).

$Assertion:$ Plants convert fatty' acids into glucose.

$Reason:$ Plants have peroxisomes.

Both (a) and (r) are true and (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
(a) is false but (r) is true

GATE BT 2012 | Question: 34

Sun, 25 Mar 2018 08:38:45 +0000

Determine the correctness or otherwise of the following $Assertion$ (a) and $Reason$ (r).

$Assertion:$ The production of secondary metabolites in plant cell cultures is enhanced by the addition of elicitors.

$Reason:$ Elicitors induce the expression of enzymes responsible for the biosynthesis of secondary metabolites.

Both (a) and (r) are true but (r) is not the correct reason for (a)
Both (a) and (r) are true but (r) is the correct reason for (a)
(a) is true but (r) is false
(a) is false but (r) is true

GATE BT 2012 | Question: 33

Sun, 25 Mar 2018 08:38:45 +0000

Match the products in $\text{Group I}$ with the applications in $\text{Group II}$.

$\begin{array}{|C|l|C|l|} \hline &\textbf{Group I} & {} &\textbf{Group II} \\\hline P. &\text{Digoxin} & 1. &\text{Muscle relaxant} \\\hline Q. &\text{Stevioside} & 2. &\text{Anti-cancer agent} \\\hline R. &\text{Atropine} & 3. &\text{Cardiovascular disorder} \\\hline S. &\text{Vinblastine} & 4. &\text{Sweetener} \\\hline\end{array}$

$\text{P-l, Q-4, R-3, S-2}$
$\text{P-3, Q-2, R-1, S-4}$
$\text{P-3, Q-4, R-1, S-2}$
$\text{P-2, Q-3, R-1, S-4}$

GATE BT 2012 | Question: 15

Sun, 25 Mar 2018 08:38:43 +0000

During photorespiration under low $CO_2$ and high $O_2$ levels, $O_2$ reacts with ribulose1,5- bisphosphate to yield

one molecule each of 3-phosphoglycerate and 2-phosphoglycolate
two molecules of 3-phosphoglycerate
two molecules of 2-phosphoglycolate
one molecule each of 3-phosphoglycerate and glyoxylate