During an experiments mutating the conserved cysteine in the LOV1 domain of phot1 does not affect phototropic responsiveness (the seedlings bend toward blue light) whereas the equivalent mutation in LOV2 abolishes the response. What will be the conclusion has been drawn from this experiments?

a)  LOV1 domain is secondarily responsible (primarily responsible is LOV2 domain) for kinase activation and LOV1 is not is coupled with the protein region Jα-helix that’s why it does not affect phototropic responsiveness

b) These studies have demonstrated that LOV2 domain is primarily responsible for kinase activation in response to blue light

c) This is due in part to the position of LOV2 within the phototropin molecule, where it is coupled to a protein region known as the Jα-helix

d) The function of LOV2 domain is thought to play a role in receptor dimerization by accomplishing the kinase activation in response to blue light

Which of the correct conclusion drawn from the above experiment?

TLS Online TPP Program

#Question id: 12645

#Unit 6. System Physiology – Plant

Classes of secondary metabolites, have strong antimicrobial activity have been proposed to function as defenses against pathogens in the intact plant these are_____X_______,  a group of triterpenes thought to disrupt fungal membranes by binding to sterols

TLS Online TPP Program

#Question id: 12643

#Unit 6. System Physiology – Plant

Which of the following is the first polypeptide hormone discovered in plants?

TLS Online TPP Program

#Question id: 12642

#Unit 6. System Physiology – Plant

The systemic production of proteinase inhibitors in young tomato plants is triggered by a complex sequence of events such as;

1) Prosystemin is proteolytically processed to produce the short polypeptide called systemin

2) Systemin is then transported out of the wounded leaf via the phloem.

3) systemin is believed to bind to a site on the plasma membrane and initiate the biosynthesis of jasmonic acid

4) Wounded tomato leaves synthesize prosystemin, a large recursor protein

5) Systemin is released from damaged cells into the apoplast

6) Jasmonic acid eventually activates the expression of genes that encode proteinase inhibitors

Arrange the correct sequence of given above following statements ;

TLS Online TPP Program

#Question id: 12641

#Unit 6. System Physiology – Plant

 Among the diverse components of plant defense arsenals are proteins that interfere with herbivore digestion, Given some defense compound of plants in column I with its given action in column II

Column I	column II
I)  α-amylase inhibitors	a) Antidigestive proteins, block the action of herbivore proteolytic enzymes. After entering the herbivore’s digestive tract, they hinder protein digestion by binding tightly and specifically to the active site of protein-hydrolyzing enzymes such as trypsin and chymotrypsin
II) Lectins	b) block the action of the starch-digesting enzyme
III) proteinase inhibitors	c) A defensive proteins that bind to carbohydrates or carbohydrate-containing proteins. After being ingested by an herbivore, bind to the epithelial cells lining the digestive tract and interfere with nutrient absorption

Correctly match the defence compound withits action on herbivore;

TLS Online TPP Program

#Question id: 12530

#Unit 6. System Physiology – Plant

Some given hormones is also called a ubiquitous hormone?

a) Ethylene

b) Gibberellin

c) Abscisic acid

d) Brassinosteroids

TLS Online TPP Program

#Question id: 12519

#Unit 6. System Physiology – Plant

Some given  statements about biosynthesis of Abscisic acid ;

a) ABA is synthesized in almost all cells that contain chloroplasts or amyloplasts

b) ABA is a 15-carbon terpenoid, or sesquiterpenoid, which is synthesized in plants by an indirect pathway via 40-carbon carotenoid intermediates

c) Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting

d) Oxidation by ABA-8′-hydroxylases lead to ABA inactivation, ABA can also be inactivated by conjugation, but this is irreversible. Both types of inactivation are also tightly regulated.

Which of the following  combination from the above statements  is correct?