Ethanol is to be used as a substrate for single-cell protein production in a chemostat. The available equipment can achieve an oxygen transfer rate of 10 g O₂/l of liquid per hour. Assume the kinetics of cell growth on ethanol is of the Monod type, with µm = 0.5 h^–1, K_s = 30 mg/l, YX/S = 0.5 cells/g ethanol, and YO2/S = 2 g O2/g EtOH. We wish to operate the chemostat with an ethanol concentration in the feed of 22 g/L. We also wish to maximize the biomass productivity and minimize the loss of unused ethanol in the effluent. Determine the required dilution rate

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#Question id: 3274

#Section 3: Genetics, Cellular and Molecular Biology

The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information?

#Question id: 3275

#Section 3: Genetics, Cellular and Molecular Biology

When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of ________.

#Question id: 3276

#Section 3: Genetics, Cellular and Molecular Biology

Which of these conditions are always true of populations evolving due to natural selection?

Condition 1: The population must vary in traits that are heritable.

Condition 2: Some heritable traits must increase reproductive success.

Condition 3: Individuals pass on most traits that they acquire during their lifetime.

#Question id: 3277

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following describes the most likely order of events in allopatric speciation?

#Question id: 3278

#Section 3: Genetics, Cellular and Molecular Biology

What does the biological species concept use as the primary criterion for determining species boundaries?

#Question id: 3279

#Section 3: Genetics, Cellular and Molecular Biology

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