The T-cell receptor link to MHC–peptide is enhanced by interaction between MHC class II on the antigen-presenting cells with the following molecule on the T-cell:

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#Question id: 12394

#Unit 6. System Physiology – Plant

 Which one of the following fungal phytotoxin, stimulates both rapid proton extrusion and transient growth in stem and coleoptile sections?

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#Question id: 12395

#Unit 6. System Physiology – Plant

In theory, auxin could increase the rate of proton extrusion by two possible mechanisms:

I) H+-ATPase activation

II) H+-ATPase synthesis

a) Auxin involves in the activation of ATP-driven proton-pump (H+-ATPase) indirectly

b) ABPs appear to be able to activate the plasma membrane H+-ATPase in the presence of auxin

c) Activity of the H+- ATPase is repressed by the C-terminal domain of the enzyme, which can block the catalytic site  in absence of auxin

d) The protein is synthesized on the rough endoplasmic reticulum and targeted via the secretory pathway to the plasma membrane

Find out the correct explanation of given mechanisms.

TLS Online TPP Program

#Question id: 12396

#Unit 6. System Physiology – Plant

Which compound  are included in the buffer washout solution, that involved in prevent normal relocalization of PIN to the plasma membrane ?

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#Question id: 12397

#Unit 6. System Physiology – Plant

when auxin binds to its receptor is the activation of a select group of transcription factors. The activated transcription factors enter the nucleus and promote the expression of specific genes. Genes whose expression is stimulated by the activation of pre-existing  transcription factors are called primary response genes or early genes. 

a) Some of the early genes encode proteins that regulate the transcription of secondary response genes, or late genes, that are required for the short-term responses to the hormone

b) Early genes are involved in intercellular communication, or cell-to-cell signaling and some also involved in adaptation to stress

c) Secondary response genes are required for the long-term responses to the hormone. Because late genes require de novo protein synthesis, their expression can be blocked by protein synthesis inhibitors

d) Early-gene expression can also be blocked by inhibitors of protein synthesis such as cycloheximide, the time required for the expression of the early genes can be quite short, ranging from a few minutes to several hours

Which of the following is the correct prediction about primary response gene?

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#Question id: 12398

#Unit 6. System Physiology – Plant

Early auxin-responsive genes have been identified as ___

I. Genes involved in auxin-regulated growth and development

II. Gene involved in Stress response 

Given some genes below which are identified as auxin regulated growth as well as stress response gene;

a) glutathione S-transferases

b) AUX/IAA gene family

c) 1-aminocyclopropane-1-carboxylic acid (ACC) synthase

d) GH3 gene family

e) SAUR gene family

Which one of the following combination from the above early auxin responsive gene is correct?

TLS Online TPP Program

#Question id: 12399

#Unit 6. System Physiology – Plant

Early auxin genes are regulated by___