NEET Practice Questions (MCQs) with Answers & Solutions

This question tests comprehension of the conceptual simplification used in deriving the combined lens formula. 'It must, however, be borne in mind that formation of image by the first lens is presumed only to facilitate determination of the position of the final image. In fact, the direction of rays emerging from the first lens gets modified in accordance with the angle at which they strike the second lens.'

According to the NCERT text, 'In aqueous solution, the carboxyl group can lose a proton and amino group can accept a proton, giving rise to a dipolar ion known as zwitter ion. This is neutral but contains both positive and negative charges.'

The NCERT text states, 'Except glycine, all other naturally occurring $\alpha$-amino acids are optically active, since the $\alpha$-carbon atom is asymmetric.'

The NCERT text mentions, 'Most naturally occurring amino acids have L-configuration. L-Aminoacids are represented by writing the –NH2 group on left hand side.'

The NCERT text states, 'Chemically, peptide linkage is an amide formed between –COOH group and –NH2 group.'

According to the NCERT text, 'If a third amino acid combines to a dipeptide, the product is called a tripeptide. A tripeptide contains three amino acids linked by two peptide linkages.'

The NCERT text (BIOLOGY chapter) explicitly states, 'Based on number of amino and carboxyl groups, there are acidic (e.g., glutamic acid), basic (lysine) and neutral (valine) amino acids.' The Chemistry chapter further classifies, 'more carboxyl groups as compared to amino groups makes it acidic.'

The NCERT Biology text says, 'The R group in these proteinaceous amino acids could be a hydrogen (the amino acid is called glycine), a methyl group (alanine), hydroxy methyl (serine), etc.'

The NCERT Chemistry text explains, 'This behaviour [behaving like salts] is due to the presence of both acidic (carboxyl group) and basic (amino group) groups in the same molecule.'

The NCERT Chemistry text defines essential amino acids as 'those which cannot be synthesised in the body and must be obtained through diet.'