Zoology MCQs for NEET — Practice Questions with Answers

The text clearly states: 'At times, a drug/alcohol addict becomes the cause of mental and financial distress to his/her entire family and friends.'

According to the NCERT text, 'After completion of the biosynthetic stage, the product has to be subjected through a series of processes... The processes include separation and purification, which are collectively referred to as downstream processing.'

Downstream processing occurs after the biosynthetic stage. The biosynthetic stage, where the product is actually made in a bioreactor, precedes downstream processing. Quality control, formulation, and potentially clinical trials are part of making the product ready for marketing, which falls under the broader scope of downstream processing activities.

The NCERT states, 'After completion of the biosynthetic stage, the product has to be subjected through a series of processes before it is ready for marketing as a finished active product.' This highlights the end goal of downstream processing.

The NCERT explicitly states that separation and purification are part of downstream processing. While not explicitly mentioned as 'downstream processing' within the provided snippet, the summary states 'purification of the gene product, i.e., the functional protein and finally making a suitable formulation for marketing.' Formulation and marketing readiness imply quality control. Biosynthesis (iii) is the preceding stage.

Downstream processing involves separation and purification, which are essential to isolate the desired product from the cell culture, remove impurities, and prepare it for its intended use or marketing. This makes the product 'ready for marketing as a finished active product' as per the NCERT text.

Removing contaminants from the final product is a key function of downstream processing. The biosynthetic stage focuses on producing the product effectively, for example, by providing 'optimum growth conditions (temperature, pH, substrate, salts, vitamins, oxygen)' and using bioreactors for 'large yield of desired protein'.

The NCERT summary outlines the sequence: 'expression of the foreign gene... purification of the gene product, i.e., the functional protein and finally making a suitable formulation for marketing.' The purification and formulation steps constitute downstream processing, which follows the expression (production) of the protein.

The NCERT text states: 'PCR stands for Polymerase Chain Reaction. In this reaction, multiple copies of the gene (or DNA) of interest is synthesised in vitro'. This directly describes the fundamental principle of PCR.

The NCERT Figure 9.6 clearly labels the three steps in each PCR cycle as: (i) Denaturation; (ii) Primer annealing; and (iii) Extension of primers. Therefore, the correct order is Denaturation, Annealing, Extension.