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How does PCR amplify a gene of interest?
The NCERT text states: 'In this reaction, multiple copies of the gene (or DNA) of interest is synthesised in vitro using two [primers]'. This refers to the core mechanism of PCR.
To detect an infection by a pathogen using ELISA, what can be detected?
The text states: 'Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.'
Which of these diagnostic methods involves the amplification of nucleic acids?
The context specifically mentions: '...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.'
What is the primary role of Recombinant DNA technology in molecular diagnostics, as suggested by the context?
The context groups Recombinant DNA technology with PCR and ELISA as 'some of the techniques that serve the purpose of early diagnosis.' While PCR involves amplification and ELISA involves antigen-antibody interactions, recombinant DNA technology encompasses broader genetic manipulation that can facilitate accurate diagnostics.
If a healthy individual's DNA is probed with a radioactive single-stranded DNA sequence corresponding to a known pathogenic gene, and no signal is detected via autoradiography, what does this indicate?
The principle for detecting mutated genes using a probe is that 'the probe will not have complementarity with the mutated gene.' Conversely, if a probe for a pathogen gene is used and no hybridization occurs (thus no signal), it implies the complementary sequence (the pathogenic gene) is absent in the individual's DNA.
What kind of molecules are typically detected as 'antigens' in the context of ELISA for pathogen detection?
The NCERT text states: 'Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.' This clearly indicates that antigens are often proteins or glycoproteins.
Which of the following physical quantities is defined as a vector product of two vectors?
According to the NCERT text, 'Two important quantities in the study of rotational motion, namely, moment of a force and angular momentum, are defined as vector products.'
If $\vec{a}$ and $\vec{b}$ are two vectors and $\theta$ is the angle between them, the magnitude of their vector product $\vec{c} = \vec{a} \times \vec{b}$ is given by:
The NCERT text states: '(i) magnitude of $c = c = ab \sin\theta$ where a and b are magnitudes of $\vec{a}$ and $\vec{b}$ and $\theta$ is the angle between the two vectors.'
The direction of the vector product $\vec{c} = \vec{a} \times \vec{b}$ is perpendicular to:
The NCERT text specifies: '(ii) $\vec{c}$ is perpendicular to the plane containing $\vec{a}$ and $\vec{b}$'.
Which rule is commonly used to determine the direction of the vector product of two vectors?
The NCERT text describes: '(iii) if we take a right handed screw... and if we turn the head in the direction from $\vec{a}$ to $\vec{b}$, then the tip of the screw advances in the direction of $\vec{c}$. This right handed screw rule is illustrated in Fig. 6.15a.' It also mentions the right-hand rule with curling fingers.
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The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.