Individual chromosomes may lose or gain parts and the order of genes within a chromosome may become altered. These variations in the number and structure of chromosomes are termed as

TLS Online TPP Program

#Question id: 12715

#Unit 6. System Physiology – Plant

Early-acting stress sensors provide the initial signal for the stress response,  several possible examples of stress-sensing mechanisms that act early in the pathway have been identified. They include:

A) calcium channel (cyclic nucleotide-gated calcium channel) that senses changes in temperature

B) A kinase (SnRK1, a SNF1-related kinase 1) that senses energy depletion during stress

C) A plasma membrane histidine kinase (ATHK1) that senses osmotic stress

D) A leucine rich repeat receptor kinase (LRRK) protein (Srlk)

E) An endoplasmic reticulum transmembrane sensor inositol-requiring enzyme 1 (IRE1)

And activating several response after sensing these mechanisms;

i) activates hundreds of stress-response transcripts

ii) that functions as an upstream regulator of salinity responses in Arabidopsis

iii) that is required for acclimation to heat stress

iv) that is required for heat tolerance in plants

v) activates ABA-dependent and ABA-independent responses

Which of the following is the correct match the activating response with its sense mechanism;

TLS Online TPP Program

#Question id: 12716

#Unit 6. System Physiology – Plant

Some cis-elements of target genes, which are involved in the Signal perception of stress (Drought/salinity and cold) to activating tolerance, 

a) MYCRS/MYBRS

b) NACRS

c) bZIP

d) ABRE

e) MEKK1

These cis-elements are____

TLS Online TPP Program

#Question id: 12717

#Unit 6. System Physiology – Plant

During drought /salinity and cold tolerance performing Signal perception via signal transduction pathway in 

(1) ABA-dependent and   (2) ABA-independent manner and activating various transcriptional factor such as

a) MYC/MYB

b) ABRE

c) DREB1/DREB2

d) NAC

e) CRT

f) bZIP

TLS Online TPP Program

#Question id: 12718

#Unit 6. System Physiology – Plant

primary disruptions could be signaling the plant that a change in environmental conditions has occurred and that it’s time to respond by altering existing pathways or by activating stress-response pathways. At least five different types of stress-sensing mechanisms can be distinguished:

COLUMN I	COLUMN II
A) Physical sensing	i) usually results from the detection of by-products that accumulate in cells due to the uncoupling of enzymatic or electron transfer reactions, such as the accumulation of ROS during stress caused by too much light.
B) Biophysical sensing	ii) often involves the presence of specialized proteins that have evolved to sense a particular stress; for example, calcium channels that can sense changes in temperature and alter Ca2+ homeostasis.
C) Metabolic sensing	iii) refers to modifications of DNA or RNA structure that do not alter genetic sequences, such as the changes in chromatin that occur during temperature stress.
D) Biochemical sensing	iv) refers to the mechanical effects of stress on the plant or cell structure, for example, the contraction of the plasma membrane from the cell wall during drought stress.
E) Epigenetic sensing	v) might involve changes in protein structure or enzymatic activity, such as the inhibition of different enzymes during heat stress.

 

  

Match the correct sequence sensing mechanism during in stress;

TLS Online TPP Program

#Question id: 12719

#Unit 6. System Physiology – Plant

Which of the following is a key enzyme in the proline biosynthetic pathway?

TLS Online TPP Program

#Question id: 12720

#Unit 6. System Physiology – Plant

Several genes coding for enzymes associated with osmotic adjustment are turned on (up-regulated) by osmotic stress and/or salinity, and cold stress. These genes encode enzymes such as the following;

I) ∆′1-Pyrroline-5-carboxylate synthase, a key enzyme in the proline biosynthetic pathway

II) myo-Inositol 6-O-methyltransferase, a rate-limiting enzyme in the accumulation of the cyclic sugar alcohol called pinitol

III) Betaine aldehyde dehydrogenase, an enzyme involved in glycine betaine accumulation

Given following statements of gene encoding enzyme is correct?