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;

#Question id: 10346

#Unit 6. System Physiology – Plant

Nitrite reductase will convert nitrite to ammonium. There are two types of nitrite reductase characteristics given below;

a) Both nitrite reductase consist of a single 63kD polypeptide

b) In leaf chloroplasts and root plastids contain different forms of the nitrite reductase enzyme

c) In shoot nitrite reductase directly dependent on the light reaction by the ferredoxin, it activates nitrite reductase in choloroplast

d) NADPH in the roots is provided by pentose phosphate pathway, it also activate nitrite reductase in the plastids

Which of the correct statement about nitrite reductase characteristics?

#Question id: 10349

#Unit 6. System Physiology – Plant

Elevated plastid levels of glutamine stimulate the activity of glutamate synthase (also known as glutamine:2- oxoglutarate aminotransferase, or GOGAT). Given below some of the statements about GOGAT, which one of the following is incorrect?

#Question id: 10350

#Unit 6. System Physiology – Plant

Ammonium can be assimilated via an alternative pathway rather than primary pathway which involves the sequential actions of glutamine synthetase(GS) and glutamate synthase(GOGAT), these alternative pathway catalyzes by enzyme known as,

#Question id: 10351

#Unit 6. System Physiology – Plant

Plants contain two types of GOGAT; one accepts electrons from NADH, and the other accepts electrons from ferredoxin (Fd); which one of the following statements is correct?

#Question id: 10352

#Unit 6. System Physiology – Plant

which of the following amino acid that participates in the malate–aspartate shuttle to transfer reducing equivalents from the mitochondrion and chloroplast into the cytosol?

#Question id: 10353

#Unit 6. System Physiology – Plant

Aminotransferases are found in multiple organelles such as cytoplasm, chloroplasts, mitochondria, glyoxysomes, and peroxisomes, these aminotransferases one of its organelles may have a significant role in amino acid biosynthesis such as;