Which two of the following have operated to increase divergence between mosquito fish populations on island?

a. improved gene flow

b. bottleneck effect

c. sexual selection

d. founder effect

e. natural selection

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#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

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#Question id: 12412

#Unit 10. Ecological Principles

In most mammalian populations the sex ratio

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#Question id: 12413

#Unit 10. Ecological Principles

Mortality rate is calculated as