Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

 Which of the following is true for traditional and real time PCR?

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#Question id: 12255

#Unit 10. Ecological Principles

The following three panels show the change in population size over time for two species when they are found alone and when they are found together. Which kind of interaction best describes the relationship between the two species?

TLS Online TPP Program

#Question id: 12256

#Unit 10. Ecological Principles

Ant species X preys upon ant species Y. A researcher has the following set of observations regarding the behaviour of species X where aggression signifies a predatory response.

Which of the following statement(s) are correct regarding the behaviour of Species X?

(i)    A glass bead is sufficient to elicit the predatory response.

(ii)   Both chemical and non-chemical cues are involved in the predatory response.

(iii)  Chemical cues are necessary to elicit the predatory response.

(iv) Chemical cues are sufficient to elicit the predatory response

TLS Online TPP Program

#Question id: 12257

#Unit 10. Ecological Principles

Which of the following is most likely to reduce competition in sympatric, closely related species? 

TLS Online TPP Program

#Question id: 12258

#Unit 10. Ecological Principles

The acoustical receptors are destroyed on a population of larvae and rates of wasp predation are measured on the "deaf” larvae and  on  a  population  of  normal  larvae.  Based on the  curve  in  the  figure  and  on  the  concept  that animals possess sensory mechanisms that enhance survival, one could correctly predict which of the following?

TLS Online TPP Program

#Question id: 12259

#Unit 10. Ecological Principles

Which of the following is an example of exploitation competition? 

TLS Online TPP Program

#Question id: 12260

#Unit 10. Ecological Principles

Chemical competition among organisms is referred to as __________.