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?

#Question id: 10787

#Unit 6. System Physiology – Plant

Which structure represents cinnamic acid___

#Question id: 10788

#Unit 6. System Physiology – Plant

Phenyl ammonia lyase (PAL) involved in biosynthesis of phenolic compound in plants. Following are some statements regarding the action of PAL;

a) PAL catalyze conversion of phenyl alanine to p-coumaric acid

b) PAL catalyzes the conversion of phenyl alanine into trans-Cinnamic acid by elimination of an ammonia molecule

c) The activity of PAL is increased by environmental factors, such as low nutrient levels, light, and fungal infection

d) PAL is situated at a branch point between primary and secondary metabolism, so the reaction that it catalyzes is an important regulatory step in the formation of many phenolic compounds

Which of the following combinations of above statement is true?

#Question id: 10789

#Unit 6. System Physiology – Plant

Trans-cinnamic acid, p-coumaric acid, and their derivatives are simple phenolic compounds known as

#Question id: 10790

#Unit 6. System Physiology – Plant

chalcone synthase (CHS) involved in biosynthesis of phenolic compound in plants. Following are some statements regarding the action of CHS;

 a) Chalcone synthase catalyzes the conversion of p-Coumaroyl-CoA into Chalcones

 b) Substrate for Chalcone synthase is chalcone

 c) CHS activity increased by environmental factors, such as light, and fungal infection

 d) Chalcone synthase is enzyme in flavonoid biosynthesis catalyzes stepwise condensation into p-Coumaric acid by using Malonyl-CoA molecules

 Which of the following combinations of above statement is true?

#Question id: 10791

#Unit 6. System Physiology – Plant

Following are certain statements regarding furanocoumarins;

 a) furanocoumarins have an attached furan ring

 b) These compounds are toxic until they are activated by sunlight in the ultraviolet A (UV-A) region (320–400 nm)  

 c) Light activated furanocoumarins can insert themselves into the double helix of DNA and bind to the pyrimidine bases, thus blocking transcription and repair and leading eventually to cell death   

 d) Phototoxic furanocoumarins are especially abundant in members of the Umbelliferae family, including celery, parsnip, and parsley.

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

#Question id: 10792

#Unit 6. System Physiology – Plant

Compounds such as caffeic acid and ferulic acid occur in soil in appreciable amounts and have been shown,