Advanced Plant Defense Signaling – 30 MCQs (CSIR-NET Part C Pattern)
अब तुम एकदम सही दिशा में सोच रहे हो।
तुम्हें अब सिर्फ याद करने वाले नहीं, concept + logic + experimental reasoning वाले MCQs चाहिए,
जैसे CSIR-NET (Part C) में पूछे जाते हैं।
नीचे जो सेट मैंने तैयार किया है वो बिल्कुल उसी पैटर्न पर है —
कहीं दो-statement based हैं, कहीं तीन-statement वाले, कहीं data-driven concept reasoning हैं।
हर एक सवाल Plant innate immunity (PTI–ETI–HR–SAR–Signaling cross-talk) से जुड़ा है।
👉 Answers अंत में एक साथ दिए गए हैं, ताकि तुम खुद पहले solve कर सको।
🌿 Set–5: Advanced Plant Defense Signaling – 30 MCQs (CSIR-NET Part C Pattern)
1.
Consider the following statements about PTI (Pattern-Triggered Immunity):
I. PTI is initiated when PRRs recognize MAMPs/DAMPs.
II. PTI can activate MAPK cascades leading to transcriptional reprogramming.
III. PTI causes immediate HR-like cell death.
Which of the following is correct?
A. Only I and II
B. Only II and III
C. All I, II, III
D. Only I
---
2.
During ETI, which of the following features distinguishes it from PTI?
A. Stronger and sustained defense response
B. Activation of R genes (NLRs)
C. Localized hypersensitive cell death
D. All of the above
---
3.
A mutant Arabidopsis line defective in FLS2 receptor will fail to:
A. Recognize bacterial flagellin (flg22)
B. Activate MAPK-mediated transcription
C. Generate ROS burst upon bacterial exposure
D. All of the above
---
4.
Match the following PRRs with their ligands:
PRR Ligand
a. FLS2 1. EF-Tu peptide (elf18)
b. EFR 2. Chitin
c. CERK1 3. Flagellin (flg22)
Choose the correct match:
A. a-3, b-1, c-2
B. a-2, b-3, c-1
C. a-1, b-2, c-3
D. a-3, b-2, c-1
---
5.
Which of the following events occurs earliest after pathogen recognition?
A. Transcription of PR genes
B. ROS burst and ion flux
C. Callose deposition
D. SA accumulation
---
6.
NLR (NBS-LRR) proteins in plants are functionally analogous to:
A. Animal Toll-like receptors
B. Animal NOD-like receptors
C. Animal cytokine receptors
D. Animal ion channels
---
7.
In the guard hypothesis, “guardee” refers to:
A. A plant protein targeted by pathogen effectors
B. An effector secreted by pathogen
C. A PR gene product
D. A signaling molecule
---
8.
Which of the following statements is TRUE about NLR activation?
A. ATP hydrolysis is essential for its conformational switch.
B. LRR domain acts as a negative regulator until effector binding.
C. CC or TIR domains mediate downstream signaling.
D. All are true.
---
9.
During ETI, Ca²⁺ influx leads to activation of which enzyme class responsible for oxidative burst?
A. NADPH oxidases (RBOHs)
B. Peroxidases only
C. Catalases
D. Cytochrome P450s
---
10.
Consider following signaling molecules:
1. ROS
2. Nitric oxide
3. Salicylic acid
4. Ethylene
Which of them act as early mediators in HR?
A. 1 and 2
B. 2 and 3
C. 3 and 4
D. 1 and 3
---
11.
Which combination of hormones generally acts synergistically against necrotrophic pathogens?
A. SA + JA
B. JA + Ethylene
C. SA + ABA
D. JA + GA
---
12.
WRKY70 transcription factor acts as an integrator by:
A. Activating JA-responsive genes
B. Repressing JA pathway and promoting SA pathway
C. Repressing SA pathway
D. Inducing auxin signaling
---
13.
A plant mutant over-expressing NPR1 would likely show:
A. Enhanced SAR response
B. Suppressed JA-dependent defense
C. Constitutive PR gene expression
D. All of the above
---
14.
The reduced (monomeric) form of NPR1 enters the nucleus because:
A. ROS oxidation creates nuclear pores
B. Cytoplasmic thioredoxins reduce its disulfide bonds
C. Phosphorylation of IκB occurs
D. SUMOylation increases its solubility
---
15.
A mutant in ICS1 gene would be defective in:
A. Isochorismate pathway of SA biosynthesis
B. Shikimate pathway of phenylalanine synthesis
C. JA biosynthesis
D. Phenylpropanoid metabolism
---
16.
Which enzyme converts α-linolenic acid to 13-hydroperoxyoctadecatrienoic acid (13-HPOT) in JA biosynthesis?
A. Lipoxygenase (LOX)
B. AOS
C. AOC
D. OPR3
---
17.
JA biosynthetic reactions occur sequentially in:
A. Chloroplast → Peroxisome → Cytosol
B. Mitochondria → Nucleus
C. ER → Golgi → Cytosol
D. Peroxisome → Mitochondria
---
18.
The JA-Ile (bioactive form) is perceived by the receptor complex formed by:
A. COI1 and JAZ
B. NPR1 and TGA
C. WRKY and MYB
D. FLS2 and BAK1
---
19.
JAZ proteins repress defense by:
A. Binding and inhibiting MYC2 transcription factors
B. Degrading NPR1
C. Enhancing ROS generation
D. Promoting MAPK signaling
---
20.
Which compound acts as a mobile SAR signal that can be methylated and transported?
A. Methyl salicylate
B. Methyl jasmonate
C. Azelaic acid
D. Pipecolic acid
---
21.
Which metabolite derived from lysine contributes to SAR priming in distal leaves?
A. Pipecolic acid
B. Phenylalanine
C. GABA
D. Proline
---
22.
During oxidative burst, superoxide (O₂⁻) is first generated by NADPH oxidase and then dismutated to H₂O₂ by:
A. Superoxide dismutase (SOD)
B. Catalase
C. Glutathione reductase
D. Peroxidase
---
23.
Which statement is correct about Systemic Acquired Resistance (SAR)?
A. It is race-specific.
B. It is effective against a broad spectrum of pathogens.
C. It depends on JA rather than SA.
D. It is localized to infected cells only.
---
24.
A plant treated with coronatine (a JA mimic) will likely show:
A. Reversal of SA-induced stomatal closure
B. Enhanced resistance to biotrophs
C. Reduced susceptibility to necrotrophs
D. Activation of PR-1 gene
---
25.
In experimental detection of ROS burst during PTI, which reagent is used?
A. Luminol chemiluminescence assay
B. DPPH radical scavenging assay
C. Bradford reagent
D. Ninhydrin test
---
26.
Which transcription factors are most directly activated downstream of MAPK cascades in defense signaling?
A. WRKY family
B. MYC family
C. bZIP family
D. E2F family
---
27.
SA-induced ROS accumulation is tightly regulated by which redox buffer pair?
A. Ascorbate–glutathione cycle
B. Thioredoxin–ferredoxin cycle
C. NADH–NAD⁺ balance
D. Flavonoid–phenol cycle
---
28.
Which gene family encodes peroxidases responsible for lignin deposition and cell-wall strengthening during defense?
A. PRX
B. PAL
C. AOS
D. NPR
---
29.
Cross-talk question:
When both JA and SA are induced simultaneously, which transcriptional regulator mediates the antagonistic outcome?
A. WRKY70
B. MYC2
C. COI1
D. EIN3
---
30.
During HR, vacuolar collapse contributes to:
A. Programmed cell death and release of antimicrobial compounds
B. Suppression of defense signaling
C. Nutrient release for pathogen growth
D. Secondary metabolite storage
🌿 Answers (Set–5)
1️⃣ A
2️⃣ D
3️⃣ D
4️⃣ A
5️⃣ B
6️⃣ B
7️⃣ A
8️⃣ D
9️⃣ A
🔟 A
11️⃣ B
12️⃣ B
13️⃣ D
14️⃣ B
15️⃣ A
16️⃣ A
17️⃣ A
18️⃣ A
19️⃣ A
20️⃣ A
21️⃣ A
22️⃣ A
23️⃣ B
24️⃣ A
25️⃣ A
26️⃣ A
27️⃣ A
28️⃣ A
29️⃣ A
30️⃣ A
Comments
Post a Comment