Zoology MCQs for NEET — Practice Questions with Answers

From 'BIOTECHNOLOGY AND ITS APPLICATIONS': 'very low concentration of a bacteria or virus (at a time when the symptoms of the disease are not yet visible) can be detected by amplification of their nucleic acid by PCR. Can you explain how PCR can detect very low amounts of DNA? PCR is now routinely used to detect HIV in suspected AIDS patients.' This highlights PCR's sensitivity in amplifying small amounts of nucleic acid.

From 'MOLECULAR BASIS OF INHERITANCE': 'The sensitivity of the technique has been increased by use of polymerase chain reaction (PCR– you will study about it in Chapter 9). Consequently, DNA from a single cell is enough to perform DNA fingerprinting analysis.' This emphasizes that PCR amplifies the DNA, reducing the sample requirement.

The text mentions PCR's use in 'early diagnosis' for HIV and its ability to 'detect mutations in genes in suspected cancer patients'. It also introduces PCR as a method to 'synthesise multiple copies of the gene (or DNA) of interest' for recombinant DNA technology. Large-scale production of recombinant proteins involves bioreactors and downstream processing, but PCR itself is for amplifying DNA, not for producing the proteins directly.

The NCERT text states: 'In this reaction, multiple copies of the gene (or DNA) of interest is synthesised in vitro'. 'In vitro' biologically means 'in glass' or, more generally, outside a living organism, typically in a laboratory setting like a test tube.

From 'MOLECULAR BASIS OF INHERITANCE': 'The sensitivity of the technique has been increased by use of polymerase chain reaction (PCR... Consequently, DNA from a single cell is enough to perform DNA fingerprinting analysis.' This clearly indicates that PCR's amplification capability allows the use of very small sample sizes.

The text states: 'very low concentration of a bacteria or virus... can be detected by amplification of their nucleic acid by PCR.' The ability to detect something in low quantities is referred to as sensitivity.

The NCERT text states: 'Urine formation involves three main processes, i.e., filtration, reabsorption and secretion. Filtration is a non-selective process performed by the glomerulus using the glomerular capillary blood pressure.'

The NCERT text mentions: 'Filtration is a non-selective process performed by the glomerulus using the glomerular capillary blood pressure.'

The NCERT text states: 'About 1200 ml of blood is filtered by the glomerulus per minute to form 125 ml of filtrate in the Bowman’s capsule per minute (GFR).'

The NCERT text states: 'The Bowman’s capsule encloses the glomerulus to form Malpighian or renal corpuscle.'