Why do we fall ill?(CBSE-IX)

In public health, the primary cause of many diseases is the lack of basic sanitation, such as access to clean water. Drinking unclean water is a fundamental cause of waterborne diseases.

Public cleanliness and hygiene are essential for maintaining the health of every individual in a community. It is a collective effort that benefits the individual.

Individual health is influenced by both social and economic factors. Having a job and sufficient money are both necessary to access resources like food and healthcare.

Antibiotics are chemical substances produced by microorganisms or synthesized to inhibit the growth of or kill bacteria.

Antibiotics work by targeting specific cellular processes in bacteria, such as cell wall synthesis or protein production, which are referred to as biochemical pathways.

HIV (Human Immunodeficiency Virus) specifically targets and destroys CD4 cells, which are a vital part of the body's immune system.

Tetanus is caused by the bacterium Clostridium tetani, which produces a toxin that affects the nervous system.

HIV stands for Human Immunodeficiency Virus, which reflects its nature of weakening the immune system.

Both acute (short-term, severe) and chronic (long-term) diseases can be dangerous depending on severity and impact. Option A alone is incomplete - chronic diseases like cancer are also dangerous. Option B alone is incomplete - acute diseases can be fatal quickly. The question frames 'dangerous' broadly, so both types qualify.

Immunity is the biological term for resistance against specific infections or diseases. Option A (restriction) means limitation, not biological resistance. Option B (initiaition) appears to be a typo for 'initiation' and is incorrect in this context. Option D (disease) is the opposite of resistance against disease.

Antibiotics are designed to target bacterial structures or pathways. Viruses have different structures and replicate differently, so antibiotics are ineffective against them.

Whooping cough (pertussis) is a bacterial infection caused by the bacterium Bordetella pertussis, not a fungal disease.

Anaemia is a condition characterized by a deficiency in the number of red blood cells or the amount of haemoglobin in the blood. Therefore, it is marked by a decrease in haemoglobin concentration.

Antibiotics are antimicrobial substances that act against bacteria. They can target various types of bacteria and other microbes, making both 1 and 2 the correct scope.

Chemotherapy refers to the use of chemical substances to treat disease, most commonly cancer. It is a form of medical treatment.

In public health models, the first level of disease cause is often the pathogen, the second is individual health, and the third level relates to broader socio-economic factors like lack of public services.

A deficiency disease occurs when the body lacks essential nutrients, such as vitamins or minerals, due to an inadequate diet.

Eczema is a condition that makes the skin red and itchy, often leading to inflammation, fissures, and crusts. Edema refers to swelling caused by fluid retention.

Edema is the medical term for fluid retention in tissues, which is historically and colloquially referred to as dropsy. Odema is simply a variant spelling of edema.

Inflammation is the body's protective response to injury or infection, characterized by redness, heat, swelling, and pain.

Disease is a broad term that applies to any impairment of normal physiological function, which can affect humans, animals, and plants.

Prophylactic measures are actions taken to prevent a disease or infection from occurring.

Botulism is a rare but serious illness caused by a toxin produced by the bacterium Clostridium botulinum, which often thrives in improperly canned or preserved food.

The HIV virus specifically targets and destroys CD4+ helper T cells, which are crucial for the immune system to function correctly.

BCG (Bacillus Calmette-Guerin) is a tuberculosis vaccine. Option A misspells 'Bacillus', Option B misspells 'Guerin' and only lists one name, and Option C is the category not the expansion. D is technically correct as all words appear in the full name.