Nicotiana tabacum cells are cultured to high density for production of polysaccharide gum. The reactor used is a stirred tank, containing initially 100 litres medium. The maximum specific growth rate of the culture is 0.18 d^-1 and the yield of biomass from substrate is 0.5 g g^-l. The concentration of growth-limiting substrate in the medium is 3% (w/v). The reactor is inoculated with 1.5 g l^{- 1} cells and operated in batch until the substrate is virtually exhausted; medium flow is then started at a rate of 4 l d^-1. Fed-batch operation occurs under quasi-steady-state condition. The fermenter is available 275 d per year with a downtime between runs of 24 h. How much plant cell biomass is produced annually? ___________________

#Question id: 27346

#Section 5: Bioprocess Engineering and Process Biotechnology

#Question id: 14330

#Section 5: Bioprocess Engineering and Process Biotechnology

A radioactive isotope decays at a rate proportional to the amount of isotope present. If the concentration of isotope is C (mg l^-I), its rate of decay is:

A solution of the isotope ³²p is used to radioactively label DNA for hybridisation studies. The half-life of ³²p is 14.3 days. According to institutional safety requirements, the solution cannot be discarded until the activity is 1% its present value. How long will this take?____________________

#Question id: 18216

#Section 7: Recombinant DNA technology and Other Tools in Biotechnology

#Question id: 1555

#Section 2: General Biology

which type of amino acid in polypeptide position 9 is favoured interaction which MHC class 1?

#Question id: 10546

#Section 6: Plant, Animal and Microbial Biotechnology

Given below are certain statements regarding plant-pathogen interactions: which one of the following is incorrect?