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 a codominant marker?

#Question id: 3264

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following is (are) true of natural selection?

#Question id: 3265

#Section 3: Genetics, Cellular and Molecular Biology

If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring?

#Question id: 3266

#Section 3: Genetics, Cellular and Molecular Biology

One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes. The isolating mechanism is

#Question id: 3267

#Section 3: Genetics, Cellular and Molecular Biology

In a typical Mendelian population, individuals carrying gene ‘a’ in homozygous condition suffer from phenylketonurea. Those with A in homozygous condition are normal. Others, who are heterozygotic with Aa, are carriers. If the frequency of ‘a’ in a population is 0.20, what is the percentage of normal individual in the population?

#Question id: 3268

#Section 3: Genetics, Cellular and Molecular Biology

A population of insects is in Hardy-Weinberg equilibrium for a gene with alleles A = orange and a = yellow eyes. There are 91% orange and 9% yellow individuals in the population. If the fitness of the yellow phenotype suddenly drops to zero, what will be the allele frequency in the next generation?

#Question id: 3269

#Section 3: Genetics, Cellular and Molecular Biology

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of