miRNAs are encoded in the genome as segments of longer transcripts. Their characteristic structure helps identify them and predict the target genes they might regulate. Which of the following are the characteristic features of these small RNA molecules?

I. The functional form of an miRNA is typically 21 or 22 nucleotides (it can vary from 19 to 25 nucleotides).

II. The first cleavage liberates the stem-loop, called the pre-miRNA; the second generates the mature miRNA from the pre-miRNA.

III. The pre-miRNAs can be encoded by any part of a transcript: that is, they might fall within coding regions, within leader regions, or within Introns.

IV. The base pairing between miRNA and target RNA is initiated by interactions of so-called seed residues—the sequence between bases 2 and 9 of the 22-nucleotide miRNA.

#Question id: 10505

#Unit 6. System Physiology – Plant

Pseudomonas aeruginosa can alleviate the symptoms of abiotic stress by releasing of antibiotics, the amounts of the compounds released by P. aeruginosa are controlled by

#Question id: 10506

#Unit 6. System Physiology – Plant

Plant growth promoting rhizobacteria (PGPRs) such as Pseudomonas aeruginosa, that alleviate plant abiotic or biotic stress in soil by releasing of

#Question id: 10507

#Unit 6. System Physiology – Plant

Rhizobacteria function as

 a) Nitrogen fixation

 b) depositing pathogens directly into the vascular system,

 c) producing antibiotics and antifungal agents for inhibiting soil pathogens

 d) herbivore sensors by sending electrical or chemical signals to surrounding cells

 Which one of the following combination is correct?

#Question id: 10510

#Unit 6. System Physiology – Plant

Constitutive chemical defenses are effective against many different herbivores, including insects and mammals. Hemlock (Cicuta sp.) produces which toxins that a polyacetylene prolongs the repolarization of neuronal action potentials.

#Question id: 10511

#Unit 6. System Physiology – Plant

Which type of pumps inhibits digitoxin in the membranes of heart cells, leading to increased myocardial contraction?

#Question id: 10512

#Unit 6. System Physiology – Plant

Members of the Poaceae family, which includes all of the cereal crops, use benzoxazinoids alkaloids are derived from,