Practice Questions

TLS Online TPP Program

#Question id: 27248

Which of the following forces can stabilize a normal DNA double-helix?

#Section 3: Genetics, Cellular and Molecular Biology

Base-stacking is a non-covalent interaction that occurs between the relatively hydrophobic bases in the interior of the helix.
Base-pairing is a non-covalent interaction that occurs between adjacent bases in the same strand of the DNA molecule.
The hydrophilic sugar-phosphate groups are on the exterior of the helix where they can interact with each other.
The deoxyribose rings form N-glycosidic bonds with the phosphate groups that link neighboring nucleotides.

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TLS Online TPP Program

#Question id: 14220

#Section 5: Bioprocess Engineering and Process Biotechnology

A value of kLa = 30 h^-1 has been determined for a fermenter at its maximum practical agitator rotational speed and with air being sparged at 0.5 l gas/l reactor volume-min. E. coli with a qO2 of 10 mmol O2/g-dry wt-h are to be cultured. The critical dissolved oxygen concentration is 0.2 mg/l. The solubility of oxygen from air in the fermentation broth is 7.3 mg/l at 30⁰C.

What maximum concentration of E. coli can be sustained in this fermenter under aerobic conditions?

TLS Online TPP Program

#Question id: 3554

#Section 3: Genetics, Cellular and Molecular Biology

The diploid cell with 6 pairs of chromosomes can divide. How many possible different combinations of maternal and paternal chromosomes in metaphase?

TLS Online TPP Program

#Question id: 2076

#Section 3: Genetics, Cellular and Molecular Biology

An organism with a cell wall would most likely be unable to take in materials through:

TLS Online TPP Program

#Question id: 18147

#Section 2: General Biology

Which of the following physical sterilization processes can denature proteins?

TLS Online TPP Program

#Question id: 3024

#Section 2: General Biology

In a rapidly multiplying bacterial population, cell numbers increase