Read the Passage carefully and answer the questions.
There are two kinds of nucleases - exonucleases and endonucleases. Exonucleases remove nucleotides from the ends of the DNA whereas, endonucleases make cuts at specific positions within the DNA. The cutting of DNA by restriction endonucleases results in the fragments of DNA. These fragments can be separated by a technique known as gel electrophoresis. Since DNA fragments are negatively charged molecules they can be separated by forcing them to move towards the anode under an electric field through a medium/matrix. Small volume cultures cannot yield appreciable quantities of products. To produce in large quantities, the development of bioreactors, where large volumes (100-1000 litres) of culture can be processed, was required. Thus, bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial plant, animal or human cells. PCR stands for Polymerase Chain Reaction. In this reaction, multiple copies of the gene (or DNA) of interest are synthesised in vitro using two sets of primers (small chemically synthesised oligonucleotides that are complementary to the regions of DNA) and the enzyme DNA polymerase.
Bioreactors are generally used to process large volumes of culture to obtain yield of desired protein. Identify the correct volume of given culture processed by a bio-reactor?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 100-1000 litres
A bioreactor is a large vessel in which raw materials are changed into a product by living cells, such as microbes or plant, animal or human cells. It keeps the best conditions for growth: temperature, pH, substrate, salts, vitamins and oxygen. A small flask culture cannot give enough product. So bioreactors were developed to process large volumes of culture, 100-1000 litres.
Option (2) 10-1000 litres has the right upper limit, but 10 litres is too small to count as large-scale culture. The other two ranges are not the bioreactor volumes given in NCERT.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.