Mix Example - WHY DO WE FALL ILL? Questions in English

(A) Typhoid is a bacterial disease caused by the bacterium $Salmonella$ $typhi$.
$AIDS$ is caused by the $HIV$ virus.
Dengue is caused by the Dengue virus.
Influenza is caused by the Influenza virus.
Therefore,Typhoid is the correct answer as it is not a viral disease.

(B) Cholera is caused by the bacterium $Vibrio \text{ cholerae}$.
Anthrax is caused by the bacterium $Bacillus \text{ anthracis}$.
Tuberculosis is caused by the bacterium $Mycobacterium \text{ tuberculosis}$.
Influenza is a viral disease caused by the influenza virus. Therefore, it is not a bacterial disease.

(C) Typhoid is a bacterial disease caused by $Salmonella$ $typhi$.
It is not transmitted by a mosquito vector.
It spreads primarily through the consumption of contaminated food and water.

(D) The question asks to identify the disease $NOT$ caused by bacteria.
$A$, $B$, and $C$ (Typhoid, Anthrax, and Tuberculosis) are all caused by bacteria.
Typhoid is caused by $Salmonella \text{ } typhi$.
Anthrax is caused by $Bacillus \text{ } anthracis$.
Tuberculosis is caused by $Mycobacterium \text{ } tuberculosis$.
Malaria is caused by a protozoan parasite of the genus $Plasmodium$.
Therefore, the correct answer is $D$.

(A) The correct answer is $A$ (Malaria).
$1$. Malaria is caused by protozoans of the genus $Plasmodium$ (e.g.,$Plasmodium$ $vivax$,$Plasmodium$ $falciparum$).
$2$. Influenza is a viral disease caused by the influenza virus.
$3$. $AIDS$ ($Acquired$ $Immuno$ $Deficiency$ $Syndrome$) is caused by the $HIV$ ($Human$ $Immunodeficiency$ $Virus$),which is a retrovirus.
$4$. Cholera is a bacterial disease caused by the bacterium $Vibrio$ $cholerae$.

(B) Common cold and chicken pox are acute diseases,meaning they last for a short duration and do not have long-term effects on health.
Stress can be managed or reduced by making lifestyle changes.
Chewing tobacco contains harmful chemicals like nicotine and carcinogens,which cause chronic damage to the body,such as oral cancer and cardiovascular issues,and these effects persist for a long time even after the individual stops using it.

(C) Diseases or conditions like high blood pressure,genetic abnormalities,and blood cancer are non-infectious and cannot be transmitted through contact with an infected person.
Sneezing is a common mechanism for the transmission of pathogens (such as viruses or bacteria) that cause infectious diseases like the common cold,influenza,or tuberculosis.
When an infected person sneezes,they release droplets containing pathogens into the air,which can then be inhaled by a healthy person,leading to infection.
Therefore,sneezing is the correct answer as it is associated with the spread of communicable diseases.

(B) $AIDS$ (Acquired Immuno Deficiency Syndrome) is caused by the $HIV$ virus. It is transmitted through the exchange of bodily fluids such as blood,semen,vaginal fluids,and breast milk. It is also transmitted through unprotected sexual contact and the use of contaminated needles. However,$AIDS$ is not transmitted through casual physical contact such as hugging,shaking hands,or sharing personal items,as the virus does not survive long outside the human body and is not present in sweat or saliva in sufficient quantities to cause infection.

(A) All anti-bacterial medicines work by blocking specific metabolic pathways in bacteria,which prevents their growth and spread.
In contrast,viruses have very few biochemical mechanisms of their own.
They rely heavily on the host cell's machinery to replicate and survive.
Because they lack independent metabolic processes,it is extremely difficult to design drugs that target the virus without harming the host's own cellular processes.
Therefore,creating anti-viral drugs is significantly more challenging than creating anti-bacterial medicines.

(B) Kala-azar,also known as visceral leishmaniasis,is caused by the protozoan parasite $Leishmania$ $donovani$.
It is transmitted to humans through the bite of an infected female sandfly.

(C) Living in overcrowded and poorly ventilated spaces facilitates the transmission of pathogens through the air. When many people share a small,enclosed space with poor air circulation,droplets containing infectious agents released by an infected person can easily be inhaled by others,thereby increasing the risk of air-borne diseases.

(D) Pneumonia is a respiratory disease caused by bacteria like $Streptococcus \text{ } pneumoniae$. It is primarily transmitted through the air via droplets released when an infected person coughs or sneezes. In contrast, Dengue, Malaria, and Encephalitis are vector-borne diseases transmitted by mosquitoes.

(A) Individual health depends on both personal and community health factors.
While good economic conditions,social equality,and a clean environment are essential for maintaining health,living in a large and well-furnished house is not a direct requirement for health.
If a large and well-furnished house is not clean or lacks proper ventilation,it cannot ensure health.
Therefore,living in a large and well-furnished house is not as important as the other factors listed.

(B) The statement 'Peptic ulcers are caused by eating acidic food' is incorrect. Peptic ulcers are primarily caused by a bacterium known as $Helicobacter \text{ } pylori$, not by dietary acidity. While stress and spicy food can exacerbate symptoms, they are not the root cause.

(C) Mosquitoes act as vectors for various serious diseases such as $Malaria$, $Dengue$, and $Chikungunya$. They transmit pathogens from an infected person to a healthy person. Therefore, it is essential to prevent their breeding in our surroundings to maintain public health.

(D) Vaccination works by introducing a weakened or inactive form of a pathogen into the body. This triggers the immune system to recognize the pathogen and produce specific antibodies. Consequently,it creates immunity in the body against the particular disease for which the vaccine is administered,allowing the body to fight off the infection if exposed in the future.

(A) Hepatitis is a viral disease. Hepatitis $A$ and $E$ are primarily transmitted through the consumption of contaminated water and food. Hepatitis $B$,$C$,and $D$ are transmitted through the exchange of infected body fluids,such as blood or sexual contact. Given the options provided,contaminated water is a primary mode of transmission for several types of hepatitis.

(B) Vectors are living organisms that act as carriers of disease-causing pathogens. They transmit infectious agents from an infected individual to a healthy individual without necessarily causing the disease themselves. Common examples include mosquitoes,ticks,and fleas.

(N/A) Acute diseases are those that last for a very short period of time. Examples: Viral fever,Common cold.
$(b)$ Chronic diseases are those that last for a long time,even as much as a lifetime. Examples: Elephantiasis,Tuberculosis $(TB)$.
$(c)$ Infectious diseases are caused by biological agents (pathogens) and can spread from an infected person to a healthy person. Examples: Smallpox,Chickenpox.
$(d)$ Non-infectious diseases are not caused by pathogens and do not spread from one person to another. Examples: Diabetes,Goitre.

(N/A) The two diseases caused by protozoans and their causal organisms are:
$(i)$ Malaria: Caused by the protozoan $Plasmodium$.
$(ii)$ Sleeping sickness: Caused by the protozoan $Trypanosoma$.
(Alternatively,Kala-azar caused by $Leishmania$ is also a correct example.)

(N/A) $(i)$ The bacterium that causes peptic ulcers is $Helicobacter \, pylori$.
$(ii)$ This pathogen was discovered for the first time by Robin Warren and Barry Marshall in $1982$.

(N/A) An antibiotic is a chemical substance produced by microorganisms (such as bacteria or fungi) that can inhibit the growth of or kill other pathogenic microorganisms,particularly bacteria.
Examples of antibiotics include $Penicillin$ and $Streptomycin$.

(N/A) Pneumonia is an infectious or communicable disease because it spreads from an infected person to a healthy person.
$(b)$ Many skin diseases,such as ringworm,are caused by fungi.
$(c)$ Antibiotics are medicines that specifically target and block biochemical pathways essential for the growth and survival of bacteria.
$(d)$ Living organisms that carry infectious agents from an infected host to a healthy person are known as vectors (e.g.,mosquitoes).

(A-D) Hepatitis targets the liver.
$(b)$ Fits or unconsciousness targets the brain.
$(c)$ Pneumonia targets the lungs.
$(d)$ Fungal disease targets the skin.

(N/A) Edward Jenner was the first person to discover the vaccine for smallpox in $1796$.
Vaccines are biological preparations that provide active acquired immunity to a particular infectious disease.
Two diseases that can be prevented by using vaccines are smallpox and polio.

(N/A) Chronic,long-term effect
$(b)$ Acute
$(c)$ Health
$(d)$ Infectious/communicable
$(e)$ Fungi

(N/A) Infectious diseases are caused by pathogens (like bacteria, viruses, fungi, or parasites) and can spread from one person to another. Non-infectious diseases are not caused by pathogens and do not spread between individuals.
$(a)$ $AIDS$: Infectious (caused by $HIV$)
$(b)$ Tuberculosis: Infectious (caused by $Mycobacterium$ $\text{tuberculosis}$)
$(c)$ Cholera: Infectious (caused by $Vibrio$ $\text{cholerae}$)
$(d)$ High blood pressure: Non-infectious (lifestyle/genetic factors)
$(e)$ Heart disease: Non-infectious (lifestyle/genetic factors)
$(f)$ Pneumonia: Infectious (caused by bacteria or viruses)
$(g)$ Cancer: Non-infectious (uncontrolled cell division)

(N/A) Antibiotics are chemical substances produced by certain micro-organisms that can kill or inhibit the growth of other disease-causing micro-organisms.
Two major groups of micro-organisms from which antibiotics are extracted are:
$1$. $Bacteria$ (e.g.,$Streptomyces$ species used to produce streptomycin).
$2$. $Fungi$ (e.g.,$Penicillium$ species used to produce penicillin).

(A) Vector-borne diseases are those that are transmitted to humans by vectors such as mosquitoes,ticks,or flies.
Three examples of such diseases are:
$1$. Malaria: Transmitted by the female $Anopheles$ mosquito.
$2$. Dengue: Transmitted by the $Aedes$ $aegypti$ mosquito.
$3$. Chikungunya: Also transmitted by the $Aedes$ mosquito.

(N/A) Balanced diet is necessary for maintaining a healthy body. Food is essential for the growth and development of the body. $A$ balanced diet provides raw materials and energy in appropriate amounts,including proteins,carbohydrates,fats,and minerals,which are essential for the proper growth and functioning of a healthy body.
$(b)$ The health of an organism depends upon the surrounding environmental conditions. Health is a state of being well enough to function physically,mentally,and socially,and these states depend on the surrounding environment. For example,if there are unhygienic conditions in the surrounding area,it is likely that we may get infected or diseased.
$(c)$ Our surrounding area should be free of stagnant water. This is because many water-borne diseases and insect vectors (like mosquitoes) flourish in stagnant water,which causes diseases in human beings.
$(d)$ Social harmony and good economic conditions are necessary for good health. Human beings live in societies and different localities,which determine the social and physical environment; therefore,both must be kept in harmony. Public cleanliness is important for individual health. For better living conditions,money is required. We need good food for a healthy body,which requires economic stability. Furthermore,for the treatment of diseases,one needs to be in a good economic condition.

(N/A) disease is a condition in which the normal functioning of the body or a part of it is impaired or disturbed, leading to adverse effects on health.
Types of diseases:
$1$. Acute Diseases: These are diseases that last for a very short period. Examples: $\text{Common cold}$, $\text{influenza}$, $\text{fever}$.
$2$. Chronic Diseases: These are diseases that persist for a long time, sometimes even for a lifetime, and have long-term adverse effects on health. Examples: $\text{AIDS}$, $\text{tuberculosis}$, $\text{diabetes}$.
$3$. Infectious (Communicable) Diseases: These diseases are caused by pathogens and can spread from an infected person to a healthy person. Examples: $\text{Malaria}$, $\text{typhoid}$, $\text{cholera}$.
$4$. Non-infectious (Non-communicable) Diseases: These diseases do not spread from an infected person to a healthy person. They are often caused by lifestyle factors, genetic disorders, or metabolic issues. Examples: $\text{Cancer}$, $\text{hypertension}$, $\text{arthritis}$.
Non-infectious diseases can be further categorized into:
$(a)$ Lifestyle Diseases: $\text{Diabetes}$, $\text{hypertension}$.
$(b)$ Genetic Diseases: $\text{Haemophilia}$, $\text{sickle-cell anemia}$.

(N/A) When the functioning or the appearance of one or more systems of the body changes for the worse,it produces certain abnormal signs of the disease. These visual or felt changes in human beings are called symptoms. Symptoms provide an indication of the presence of a particular disease.
Example $(i)$: Lesions on the skin are symptoms of chickenpox.
Example $(ii)$: Cough is a symptom of a lung infection.

(B) The immune system of our body acts as a specialized defense mechanism designed to fight against pathogenic microbes.
It consists of various types of white blood cells and proteins that identify,attack,and eliminate harmful pathogens,thereby preventing infections and keeping our body healthy.

(N/A) To justify the principle of "prevention is better than cure", the following precautions should be taken:
$(1)$ Maintaining personal and environmental hygiene to prevent the growth of pathogens.
$(2)$ Creating awareness about the nature of diseases and their causal organisms.
$(3)$ Consuming a balanced diet to strengthen the immune system.
$(4)$ Regular medical check-ups for early detection and prevention of potential health issues.

(N/A) Some children have a weaker immune system due to various factors.
$1$. $A$ child may not be receiving a balanced diet,leading to malnutrition.
$2$. $A$ child might be living in a congested and unhygienic environment,increasing exposure to pathogens.
$3$. $A$ child may not have access to clean drinking water,which increases the risk of water-borne diseases.
These factors make certain children more susceptible to falling ill compared to others living in the same area.

(A) Antibiotics are chemical substances that specifically target and block the biosynthetic pathways of bacteria.
Since viruses do not possess their own metabolic machinery or biosynthetic pathways,they rely entirely on the host cell's machinery to replicate.
Because antibiotics are designed to disrupt bacterial-specific processes (like cell wall synthesis or protein synthesis in prokaryotes),they have no target to act upon in viruses,rendering them ineffective against viral infections.

(N/A) Our body possesses a robust immune system that constantly fights against invading microbes.
We have specialized cells,such as white blood cells,that are designed to identify and eliminate pathogenic microbes.
When infectious microbes enter the body,these immune cells become active and attempt to destroy the pathogens.
If the immune system is successful in removing or neutralizing the pathogen before it can cause significant damage or multiply uncontrollably,we remain disease-free.
Therefore,exposure to infectious microbes does not always lead to the development of a noticeable disease.

(N/A) For a person to remain healthy,the following four factors are essential:
$(i)$ Clean surrounding environment: $A$ clean environment prevents the spread of air-borne and water-borne diseases.
$(ii)$ Personal hygiene: Maintaining cleanliness of the body helps in preventing infectious diseases.
$(iii)$ Proper and balanced nutrition: Sufficient and nutritious food is necessary to strengthen the immune system of the body.
$(iv)$ Immunization: Timely vaccination against severe diseases provides protection and prevents illness.

(N/A) $AIDS$ stands for Acquired Immuno Deficiency Syndrome.
$AIDS$ is caused by the $HIV$ virus, which enters the body through sexual contact, blood transfusion, or other means.
Once inside, the virus spreads to the lymph nodes throughout the body and severely damages the immune system.
Because the immune system is compromised, the body can no longer fight off minor infections.
Consequently, simple infections like a common cold can escalate into pneumonia, or a minor gut infection can lead to severe diarrhoea and blood loss.
Since $AIDS$ does not present a single specific set of symptoms but rather manifests as a complex collection of various diseases and symptoms resulting from a weakened immune system, it is classified as a 'Syndrome' rather than a single disease.

(N/A) An infectious disease is a disease caused by pathogens (such as bacteria,viruses,fungi,or parasites) that can spread from an infected person to a healthy person through various modes of transmission like air,water,food,or physical contact.
Example: $Common \ cold$ or $Chickenpox$.

(N/A) The public health programme of childhood immunisation includes vaccines for several infectious diseases. Any two of the following can be named:
$(i)$ Tuberculosis
$(ii)$ Polio
$(iii)$ Hepatitis $B$
$(iv)$ Diphtheria
$(v)$ Tetanus

(N/A) Regularly breathing in polluted air can lead to various respiratory diseases. Two common examples are:
$1$. Bronchitis: Inflammation of the lining of the bronchial tubes.
$2$. Asthma: $A$ condition in which airways narrow and swell and may produce extra mucus.

(N/A) Two diseases for which vaccinations are available are Tuberculosis (prevented by the $BCG$ vaccine) and Typhoid (prevented by the Typhoid vaccine).

(A) Non-infectious diseases are caused by factors that are not external pathogens like microbes.
These causes are typically internal or intrinsic to the body.
Examples include genetic disorders,hormonal imbalances,nutritional deficiencies,and lifestyle-related issues.
Unlike infectious diseases,these cannot be transmitted from one person to another through contact or vectors.

(B) Communicable diseases are those illnesses that can spread from an infected person to a healthy person through various means such as air,water,food,or physical contact.
These diseases are caused by microbial agents like bacteria,viruses,fungi,or parasites.
Because these pathogens can be transmitted from one individual to another,the diseases they cause are termed as communicable or infectious diseases.

(B) Immunity is defined as the overall ability of the host to fight the disease-causing organisms,conferred by the immune system.
It involves the presence of specialized proteins called antibodies in our body that target specific disease-causing microorganisms known as antigens.
When these antigens enter our body,the immune system recognizes them and produces specific antibodies to neutralize or destroy them,thereby preventing the disease.

(N/A) $(i)$ Kala-azar is caused by the protozoan parasite $Leishmania$ $donovani$.
$(ii)$ Sleeping sickness is caused by the protozoan parasite $Trypanosoma$ $brucei$.

(N/A) $(i)$ The disease is $AIDS$ (Acquired Immuno Deficiency Syndrome).
$(ii)$ The pathogen responsible for $AIDS$ is the $Human$ $Immunodeficiency$ $Virus$ $(HIV)$.

(N/A) Local effects: These are restricted to the site of injury or infection,such as swelling,redness,pain,or heat.
General effects: These affect the entire body,such as fever.

(A) If the bacteria enter through the nose,they travel to the lungs and cause pulmonary tuberculosis.
$(b)$ If the bacteria enter through the mouth,they can affect the gut lining and potentially spread to other organs like the liver.