Nutrient medium is to be heated from 10⁰C to 28⁰C is a single-pass countercurrent shell-and-tube heat exchanger before being pumped into a fed-batch fermenter. Medium passes through the tubes of the exchanger; the shell-side fluid is water which enters with flow rate 3 x 10^4 kg h^- 1 and temperature 60⁰C pre-heated medium is required at a rate of 50 m^3 h^-1. The density, viscosity and heat capacity of the medium are the same as water; the thermal conductivity of the medium is 0.54 Wm^- 1 ⁰C^ - 1. It is proposed to use 30 steel tubes with inner diameter 5 cm; the tubes will be arranged in line. The pipe wall is 5-mm thick; the thermal conductivity of the metal is 50 Wm^- 1 ⁰C^ - 1. The maximum linear shell-side fluid velocity is estimated as 0.15 m s^-1.  Determine the heat-transfer area. ____________

#Question id: 3280

#Section 3: Genetics, Cellular and Molecular Biology

Small populations are threatened by the loss of genetic diversity from

a. Inbreeding

b. Genetic drift

c. Limited mating

#Question id: 3282

#Section 3: Genetics, Cellular and Molecular Biology

Natural selection results in different forms of plants which can survive in contaminated or uncontaminated soil. Type of natural selection is

#Question id: 3283

#Section 3: Genetics, Cellular and Molecular Biology

if the forward ( p in to q) and reverse ( q in to p) mutation rates for alleles at a locus are 1×10−1 and 1×10−2 per generation, respectively and the allelic frequencies are p = 0.20 and q = 0.80. if you assuming random matting population. Which of the following observation correct?

#Question id: 3284

#Section 3: Genetics, Cellular and Molecular Biology

The fitness of three genotype are A1A1 < A1A2 = A2A2) Which of the following observation correct?

#Question id: 3285

#Section 3: Genetics, Cellular and Molecular Biology

Natural selection continually operates on each species to keep up with improvements made by competing species; each species’ environment deteriorates as its competitors evolve new adaptations. This is known as

#Question id: 3286

#Section 3: Genetics, Cellular and Molecular Biology

 In a human population, the gene frequencies of the alleles for the ABO system are as follows:

A = 29%                         B = 7%                                    0=64%

Assuming complete random mating and Hardy-Weinberg equilibrium,

What are the blood type A frequencies in this population?