A steam steriliser is used to sterilise liquid medium for fermentation. The initial concentration of contaminating organisms is 10⁸ per litre. For design purposes, the final acceptable level of contamination is usually taken to be 10^-3cells; this corresponds to a risk that one batch in a thousand will remain contaminated even after the sterilisation process is complete. For how long should 1 m³ medium be treated if the temperature is 140⁰C ________________.

        To be safe, assume that the contaminants present are spores of Bacillus stearothermophilus, one of the most heat-resistant microorganisms known. For these spores the activation energy for thermal death is 283 kJ gmo1^-1 and the Arrhenius constant is 10^36.2 s^-1

#Question id: 3337

#Section 3: Genetics, Cellular and Molecular Biology

Small populations are threatened by a least loss of genetic variability is due to

#Question id: 3338

#Section 3: Genetics, Cellular and Molecular Biology

If the expected frequency of heterozygotes in a population (based on the Hardy–Weinberg law) is 0.4, but the observed frequency is 0.2, what is the inbreeding coefficient?

#Question id: 3339

#Section 3: Genetics, Cellular and Molecular Biology

In a plant species, flower color locus either homozygous or heterozygous with genotype RR-red, Rr- pink and rr- white. The Proportional of pink flower in generation 0 is .50.  What is the level of remaining pink flower in a third generation of repeated selfing? 

#Question id: 3340

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following statements is NOT correct regarding effect of genetic drift?

#Question id: 3341

#Section 3: Genetics, Cellular and Molecular Biology

In a given population of 400 individuals, 64 percent of population is caused  cancer due to completely dominat allele B. Assuming the population is in Hardy- Weinberg equilibrium, which of the following is the expected proportion of individuals who are not expected to develop the cancer?

#Question id: 3342

#Section 3: Genetics, Cellular and Molecular Biology

Neutral alleles are those that do not alter fitness and average reproductive success does not differ between individuals that carry one neutral allele or the other. The frequencies of these neutral alleles may change in a population by