NEET Practice Questions (MCQs) with Answers & Solutions

The NCERT states: 'Recombinant DNA technology has allowed the production of antigenic polypeptides of pathogen in bacteria or yeast. Vaccines produced using this approach allow large scale production and hence greater availability for immunisation, e.g., hepatitis B vaccine produced from yeast.'

The NCERT explicitly provides an example: 'e.g., hepatitis B vaccine produced from yeast' as a vaccine developed using recombinant DNA technology.

The NCERT highlights: 'Vaccines produced using this approach allow large scale production and hence greater availability for immunisation...'

The NCERT defines active immunity: 'When a host is exposed to antigens... antibodies are produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation... induce active immunity.'

Passive immunity involves receiving pre-formed antibodies (mother's milk, placental transfer, antitoxins, anti-venom). Vaccination against polio stimulates the body's own immune system to produce antibodies, which is active immunity.

The NCERT states: 'The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant.' This is an example of passive immunity.

The NCERT lists: 'Awareness about diseases and their effect on different bodily functions, vaccination (immunisation) against infectious diseases, proper disposal of wastes, control of vectors and maintenance of hygiene in food and water resources are necessary for achieving good health.' Vaccination is directly mentioned as part of maintaining good health and disease awareness.

According to the NCERT text, 'A hydrocarbon is termed saturated if it contains only carbon-carbon single bonds.' This means all carbon valencies are satisfied by single bonds with other carbon or hydrogen atoms.

The NCERT states, 'An alkyl group is named by substituting ‘yl’ for ‘ane’ in the corresponding alkane.' For example, methane ($CH_4$) becomes methyl ($-CH_3$).

The NCERT text states, 'The carbon atoms of the parent chain are numbered...in such a way that the branched carbon atoms get the lowest possible numbers.' This ensures the lowest locant set for substituents.