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TLS Online TPP Program

#Question id: 4313

Which of the following statements best describes the characteristics of siRNA?

#Unit 3. Fundamental Processes

  1. a double-stranded RNA, one of whose strands can complement and inactivate a sequence of mRNA

  2. a single-stranded RNA that can, where it has internal complementary base pairs, fold into cloverleaf patterns

  3. a double-stranded RNA that is formed by cleavage of hairpin loops in a larger precursor

  4. a portion of rRNA that allows it to bind to several ribosomal proteins in forming large or small subunits

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TLS Online TPP Program

#Question id: 12407

#Unit 6. System Physiology – Plant

ABA is synthesized via _____A________, the biosynthetic processes  occur in_____B_____and ____C_____.
TLS Online TPP Program

#Question id: 12408

#Unit 6. System Physiology – Plant

Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting highly regulated step in ABA synthesis that produces the 15-carbon precursor molecule xanthoxin in
TLS Online TPP Program

#Question id: 12409

#Unit 6. System Physiology – Plant

The Chemical Structure of ABA Determines Its Physiological Activity, 15 carbon compound 
a) The orientation of the carboxyl group at carbon 2 determines the cis and trans isomers of ABA. Nearly all the naturally occurring ABA is in the cis form
b) S enantiomer is the natural form; commercially available synthetic  ABA is a mixture of approximately equal amounts of the S and R forms.
c) The S enantiomer is the only one that is active in fast responses to ABA, such as stomatal closure
d) In long-term responses, such as seed maturation, only R-enantiomers are active
e) In contrast to the cis and trans isomers, the S and R forms cannot be interconverted in the plant tissue
Which of the following is the correct prediction about the active form  of ABA?
TLS Online TPP Program

#Question id: 12410

#Unit 6. System Physiology – Plant

Precursor of the ABA is___
TLS Online TPP Program

#Question id: 12411

#Unit 10. Ecological Principles

Plant population age pyramids
TLS Online TPP Program

#Question id: 12412

#Unit 10. Ecological Principles

In most mammalian populations the sex ratio