Test: Aids To Health - Class 9 MCQ

Streptomycin is an antibiotic that works by binding to bacterial ribosomes, inhibiting protein synthesis and thereby preventing the growth and reproduction of bacteria.

Artificially acquired active immunity is distinguished by the method of exposure, as it involves the introduction of antigens through vaccines, while naturally acquired active immunity results from infection by pathogens.

The local defense system primarily functions to prevent the entry of germs into the body. It consists of physical barriers like skin and mucous membranes, as well as mechanisms such as coughing and sneezing that help expel pathogens.

Antitoxins are antibodies produced in response to toxins, and their primary purpose is to neutralize poisonous substances from bacteria or other pathogens, thereby preventing harm.

Phagocytes are a type of white blood cell that play a crucial role in the immune response by engulfing and destroying pathogens through a process called phagocytosis, thereby preventing infections.

Hydrochloric acid (HCl) in the stomach plays a crucial role in immunity by killing germs that enter the body through consumed food, thus providing a barrier against infections.

Antibiotics like penicillin work primarily by preventing the formation of bacterial cell walls, which is essential for bacterial growth and survival, thus inhibiting their multiplication.

Antibodies are specialized proteins that bind to specific antigens present on pathogens, neutralizing them and marking them for destruction by other immune cells. This targeted response is crucial for effective immunity.

Innate immunity is characterized by being present at birth and providing a non-specific defense against a wide range of pathogens without requiring prior exposure or vaccination.

Memory lymphocytes are crucial in the immune system as they "remember" previous infections, allowing for a quicker and more effective immune response upon re-exposure to the same pathogen.

The DTP vaccine, which protects against diphtheria, tetanus, and pertussis (whooping cough), is administered in three doses during the first year of life to ensure early immunity.

Active acquired immunity is developed through vaccination, where the body is exposed to antigens and subsequently produces antibodies. This provides long-term protection against specific diseases.

Phenol is classified as a disinfectant, which is a stronger chemical that is harmful to skin and used on surfaces, whereas antiseptics like iodine and carbolic acid are milder and safe for application on the body.

Passively acquired immunity occurs when antibodies are transferred from the mother to the fetus through the placenta, providing temporary protection to the newborn against certain diseases.

Immunization refers to the process of developing resistance to disease-causing germs by introducing killed or weakened pathogens or their components to stimulate an immune response.

Antiseptics are safe for application on skin and are used to kill germs without causing harm, while disinfectants are strong chemicals applied to surfaces and can be harmful to skin.

Avoiding exercise is not a method of personal hygiene. In fact, regular exercise is important for overall health and contributes to hygiene by promoting good bodily functions.

The measles vaccine is based on living weakened germs. This type of vaccine stimulates a strong immune response by exposing the immune system to a harmless version of the pathogen.

Sulphonamides are a class of synthetic drugs effective against bacterial infections. They work by disrupting bacterial metabolism, making them useful in treating various infections.

World Health Day is aimed at promoting awareness about the importance of maintaining health at all levels, focusing on public health initiatives and encouraging community involvement.