General Questions in English

(A) vector is an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another.
$A$. Sand fly (vector for Leishmania),deer fly (vector for Loa loa),tsetse fly (vector for Trypanosoma),and house fly (mechanical vector for various pathogens) are all examples of vectors.
$B$. Frog,lizard,snake,and rabbit are vertebrates and not vectors.
$C$. Leishmania and Trypanosoma are pathogens (parasites),not vectors.
$D$. Frog is not a vector.
Therefore,the correct set is $A$.

(C) Relapsing fever is a vector-borne disease caused by bacteria of the genus $Borrelia$.
It is primarily transmitted to humans by the bite of infected lice or ticks.
Among the given options,$Cimex$ (commonly known as the bed bug) is a known vector for various pathogens and is associated with the transmission of relapsing fever in certain regions.
Therefore,the correct option is $C$.

(A) $Culex$ mosquitoes (specifically $Culex$ $fatigans$ or $Culex$ $quinquefasciatus$) act as biological vectors for the transmission of the filarial worm $Wuchereria$ $bancrofti$,which causes Filariasis (Elephantiasis).
- Housefly transmits diseases like Typhoid and Cholera,not Yellow fever.
- Body louse transmits Typhus fever,not Typhoid.
- Sandfly transmits Kala-azar (Leishmaniasis),not Plague.

(D) Rocky Mountain spotted fever is an acute rickettsial disease characterized by high fever,chills,and pain in muscles and joints.
It is caused by the bacterium $Rickettsia \ rickettsii$,which is transmitted to humans through the bite of an infected tick.
Therefore,the tick acts as the vector for this disease.

(C) Congenital diseases are defined as medical conditions or abnormalities that are present at the time of birth.
These conditions are typically caused by genetic factors,developmental issues during pregnancy,or environmental influences affecting the fetus in the womb.
In contrast,acquired diseases are those that develop during an individual's lifetime.

(B) Degenerative diseases are conditions in which the structure or function of the affected tissues or organs progressively deteriorates over time.
These diseases are typically caused by the gradual breakdown or degeneration of cells and tissues,often due to aging,lifestyle factors,or genetic predisposition.
Examples include Alzheimer's disease,Parkinson's disease,and osteoarthritis,where specific tissues lose their functional integrity.

(C) Any disease-producing agent or micro-organism is termed a pathogen.
Pathogens include bacteria,viruses,fungi,protozoans,and helminths that cause diseases in humans and other organisms.

(C) The diseases mentioned are transmitted as follows:
$1$. Malaria,dengue fever,and yellow fever are transmitted by mosquitoes (e.g.,$Anopheles$,$Aedes$).
$2$. Filaria is also transmitted by the bite of infected mosquitoes (e.g.,$Culex$).
$3$. Sleeping sickness is transmitted by the tsetse fly $(Glossina)$.
Since all these vectors (mosquitoes and tsetse flies) belong to the class $Insecta$,the most accurate collective term is insects.

(A) Epidemiology is the branch of medicine that deals with the incidence,distribution,and possible control of diseases and other factors relating to health. It specifically focuses on how diseases are distributed in populations and the factors that influence or determine this distribution,including the mode of transmission.

(B) Infectious or communicable diseases are those diseases which are easily transmitted from one person to another.
These diseases are caused by pathogens such as bacteria,viruses,fungi,or parasites.
Examples include the common cold,influenza,and $COVID$-$19$.

(C) Health is defined as a state of complete physical,mental,and social well-being and not merely the absence of disease or infirmity.
According to the biopsychosocial model of health,the body and mind are intimately related.
Physical health (the body) and mental health (the mind) influence each other significantly,as psychological stress can manifest as physical symptoms and vice versa.

(A) Mental illness is a significant public health concern. According to epidemiological studies,approximately $1\%$ of the global population suffers from serious mental illnesses,such as schizophrenia or severe bipolar disorder. Therefore,the correct option is $A$.

(D) The correct answer is $10\%$.
Epidemiological studies indicate that approximately $10\%$ of the general population suffers from mild mental disorders,which can include conditions like anxiety,mild depression,or stress-related issues.

(B) According to general health statistics and epidemiological studies in India,it is estimated that approximately $6-7$ million people suffer from various forms of mental illnesses. Therefore,option $B$ is the correct answer.

(C) Mental illness is characterized by significant disturbances in an individual's cognition,emotional regulation,or behavior.
Specifically,abnormal changes in thinking,perception,and judgement (cognitive processes) are key indicators.
Additionally,abnormal changes in feeling (emotional state) and memory are also significant signs of mental illness.
Therefore,both $(a)$ and $(b)$ are correct.

(D) Mental illness is a complex condition influenced by a combination of biological,psychological,and environmental factors.
$A$. Hereditary factors (genetics) play a significant role in many mental health conditions.
$B$. Childhood experiences,such as trauma or neglect,are well-documented contributors to mental health issues.
$C$. Changes in brain structure or neurochemistry are fundamental to the pathology of many psychiatric disorders.
$D$. Rheumatic fever is an inflammatory disease caused by a bacterial infection ($Streptococcus$ $pyogenes$) and is not a direct cause of mental illness. Therefore,it is the correct answer.

(D) Mental illness is a complex condition influenced by a combination of biological,psychological,and environmental factors.
However,scientific research indicates that heredity (genetics) plays a significant role in determining an individual's susceptibility or proneness to various mental health disorders,such as schizophrenia,bipolar disorder,and depression.
While environmental factors like a quarrelsome family or poverty can act as triggers,the underlying predisposition is often inherited.

(D) Mental health in children is significantly influenced by their environment and upbringing.
Affection provides emotional security,encouragement builds self-esteem,and guidance and discipline provide structure and moral development.
Lack of any of these essential components can lead to emotional instability,anxiety,or other mental health issues in a developing child.
Therefore,all the mentioned factors are crucial for the healthy psychological development of a child.

(A) The sting apparatus in honey bees ($worker$ bees) is a modified form of the ovipositor.
It is primarily used for defense and is composed of two straight grooves or lancets.

(A) The $Bordeaux$ mixture was the first fungicide discovered for the control of plant diseases. It was developed by $Pierre-Marie-Alexis$ $Millardet$ in the late $19$th century (around $1882$) to control downy mildew of grapes caused by the fungus $Plasmopara$ $viticola$.

(B) Baygon is a well-known brand of insecticide products. The primary active ingredient found in many Baygon formulations,particularly those used for household pest control,is $Propoxur$. $Propoxur$ is a carbamate insecticide that acts by inhibiting the enzyme acetylcholinesterase in insects.

(B) The correct answer is $B$.
Malathion is an organophosphate insecticide that is widely used in public health programmes,particularly in anti-malarial campaigns,to control the population of mosquito vectors.

(D) Temik is a commercial brand name for the pesticide Aldicarb.
Aldicarb belongs to the carbamate class of insecticides and is known for its high toxicity.
It acts as a systemic pesticide,meaning it is absorbed by the plant and distributed throughout its tissues to protect against pests.

(B) Triazines are a class of nitrogen-containing heterocyclic compounds. They are chemically derived from the trimerization of cyanic acid or through the reaction of ammonia with other precursors. In the context of chemical synthesis,they are structurally related to $1,3,5$-triazine,which can be synthesized from the condensation of urea or related derivatives. However,the most direct chemical precursor for the triazine ring structure is often considered to be urea or its derivatives in industrial processes.

(C) $DDT$ (Dichloro diphenyl trichloroethane) was synthesized by a German student and rediscovered by Dr. Paul Muller.
It was extensively used in the National Malaria Eradication Programme to control the population of $Anopheles$ mosquitoes,which are the vectors for malaria.

(D) Pheromones are chemical substances secreted by animals,especially insects,that trigger a social response in members of the same species.
These chemical messengers are used for various purposes including:
$1$. Acting as sex attractants to find mates.
$2$. Sending alarm signals to warn others of danger.
$3$. Marking trails to guide other members of the colony to food sources.
Therefore,all the given options are correct.

(D) The correct answer is $D$.
Streptomycin was first isolated in $1944$ by $S.A. Waksman$ and his colleagues.
It is an antibiotic derived from the soil bacterium $Streptomyces$ $griseus$.

(A) The process of inoculation of a vaccine is known as vaccination. While Edward Jenner is credited with the first successful vaccination against smallpox,Louis Pasteur $(1880s)$ is credited with establishing the scientific basis of vaccination by developing vaccines for diseases like rabies and anthrax through the attenuation of pathogens.

(C) An antibiotic is a chemical substance produced by some microorganisms (such as bacteria or fungi) that,in low concentrations,can inhibit the growth of or kill other disease-causing microorganisms.
For example,Penicillin was the first antibiotic discovered by Alexander Fleming from the mold Penicillium notatum.

(D) Steroids are a class of organic compounds that include many hormones and drugs.
They are widely used in medicine for various purposes:
$1$. Birth control: Synthetic steroids are the primary components of oral contraceptive pills.
$2$. Treatment of hormonal imbalance: Steroids are used as replacement therapy for conditions where the body does not produce enough hormones.
$3$. Treatment of auto-immune diseases: Corticosteroids are used to suppress the immune system in conditions like rheumatoid arthritis and lupus to reduce inflammation.
Therefore,all the given options are correct.

(C) The vaccine for smallpox was developed by Edward Jenner in $1796$.
He observed that milkmaids who had contracted cowpox were immune to smallpox.
He tested this hypothesis by inoculating a young boy with cowpox material and later exposing him to smallpox,which proved the boy was protected.
This discovery laid the foundation for the field of immunology.

(C) broad-spectrum antibiotic is an antimicrobial agent that is effective against a wide range of pathogenic microorganisms,including both Gram-positive and Gram-negative bacteria. Unlike narrow-spectrum antibiotics,which target specific types of bacteria,broad-spectrum antibiotics act on a variety of pathogens that belong to different groups with different structural and cell wall compositions.

(A) Antibiotics are chemical substances produced by some microorganisms that can kill or retard the growth of other disease-causing microorganisms. They are primarily effective against bacteria and fungi. However,they are generally ineffective against viruses because viruses lack the metabolic pathways that antibiotics target. Therefore,the most comprehensive answer among the choices provided,considering the broad spectrum of action,is that they target bacteria and fungi.

(A) The $WHO$ (World Health Organization) is a specialized agency of the United Nations responsible for international public health.
Its headquarters is located in Geneva,Switzerland.

(C) The correct answer is $C$.
When the donor and the recipient belong to two different species,the process is called a $Xenograft$ (also known as a $Heterograft$).
In such cases,the immune system of the recipient typically recognizes the donor tissue as foreign,leading to a high rate of rejection and a very low success rate.

(B) When a tissue is removed from one part and grafted to another part of the same body,it is called an autograft.
In this type of grafting,the success rate is high because there is no risk of immune rejection as the tissue is genetically identical to the recipient.

(C) For a successful organ or tissue transplant, the $HLA$ (human leucocyte antigen) matching is crucial to prevent graft rejection.
$1$. Identical twins (monozygotic twins) share the exact same genetic makeup, making them the best possible match.
$2$. Siblings are the next best choice because they share $50\%$ of their genes with the recipient on average.
$3$. Parents are the third choice, as they also share $50\%$ of their genes with the offspring, but the genetic diversity is often higher compared to siblings.
$4$. Unrelated donors are the least preferred due to the high probability of $HLA$ mismatch.
Therefore, the order of preference is: $Twin > Sibling > Parent > Unrelated \text{ donor}$.

(C) Alzheimer's disease is a progressive neurodegenerative disorder. It is not caused by infectious agents like viruses,bacteriophages,or bacteria. The primary pathological mechanism involves the accumulation of amyloid-beta plaques and the formation of neurofibrillary tangles composed of hyperphosphorylated tau protein in the brain. This leads to the death of nerve cells and cognitive decline. Among the given options,$C$ is the most accurate description of the underlying biological cause,as it refers to protein misfolding,which is the hallmark of the disease.

(D) Louis Pasteur is widely recognized for his pioneering work in microbiology. He is particularly famous for his studies on the role of microorganisms in fermentation and for demonstrating that microorganisms are the cause of many infectious diseases. He also developed the process of pasteurization to kill harmful microbes in food and beverages.

(A) The antivenom (antivenin) for snake bites is produced by immunizing horses with small,non-lethal doses of snake venom. The Haffkine Institute in Mumbai is a premier research organization in India known for the production of various vaccines and antivenoms,including those for snake bites.

(D) $Aspirin$ (acetylsalicylic acid) is a versatile drug.
$1$. It acts as an $Analgesic$ (painkiller) to relieve pain.
$2$. It acts as an $Antipyretic$ to reduce fever.
$3$. It acts as an $Anti-inflammatory$ agent to reduce inflammation.
$4$. It acts as an $Anticoagulant$ (blood thinner) by inhibiting platelet aggregation,which helps in preventing heart attacks and strokes.
Therefore,$Aspirin$ exhibits all these properties.

(D) Edward Jenner discovered the vaccine for smallpox in $1796$. He observed that milkmaids who had contracted cowpox were immune to smallpox. He tested this hypothesis by inoculating a young boy with cowpox material and later exposing him to smallpox,finding that the boy did not develop the disease. This laid the foundation for modern immunology.

(C) Chemical substances used to kill or prevent the growth of microorganisms on living surfaces (such as skin or wounds) are called Antiseptics.
Disinfectants are used on inanimate objects or non-living surfaces.
Therefore,the correct answer is Antiseptic.

(D) Smallpox ($Variola$ virus) was declared eradicated from India and the world by the $WHO$ in $1980$. While India has been declared polio-free,smallpox is the classic example of a disease that has been completely eradicated globally.

(D) $DPT$ is a combination vaccine that protects against three infectious diseases:
$1$. $D$ stands for Diphtheria.
$2$. $P$ stands for Pertussis (Whooping cough).
$3$. $T$ stands for Tetanus.
Therefore,the correct answer is $D$ (All of the above).

(B) $ELISA$ stands for Enzyme-Linked Immunosorbent Assay.
It is based on the principle of antigen-antibody interaction.
In this technique,an enzyme (such as alkaline phosphatase or horseradish peroxidase) is used to detect the presence of an antigen or antibody.
Therefore,alkaline phosphatase is a commonly used reagent in $ELISA$ to produce a color change,indicating the presence of the virus.

(D) Statement $(1)$ is correct: Yoga is a traditional practice used to maintain physical and mental well-being.
Statement $(2)$ is correct: Infectious diseases are highly prevalent,and almost everyone has experienced them at some point.
Statement $(3)$ is correct: $AIDS$ is caused by the $HIV$ virus and is transmissible,making it an infectious disease.
Statement $(4)$ is correct: Cancer is caused by uncontrolled cell division and is not transmitted from one person to another,hence it is a non-infectious disease.
Statement $(5)$ is correct: $A$ healthy population is more productive,which directly leads to increased economic prosperity.
Since all statements are correct,the correct option is $D$.

(C) The 'good humor' hypothesis of health was proposed by Hippocrates and the Indian Ayurveda system of medicine. They believed that health is a state of body and mind where there is a balance of certain 'humors'. Specifically,they associated the presence of 'black bile' with hot personalities and fever. However,William Harvey disproved this hypothesis by using a thermometer to measure the body temperature of individuals with black bile,showing that they had a normal body temperature. Thus,the correct answer is $(C)$.

(D) Human health is influenced by several factors:
$1$. Genetic disorders: These are deficiencies or defects that a child inherits from parents from birth.
$2$. Infections: These include diseases caused by pathogens like bacteria,viruses,fungi,and parasites.
$3$. Lifestyle: This includes the food and water we consume,rest and exercise we give to our bodies,and habits that we have or lack.
Therefore,all these factors significantly impact human health.

(D) Health is defined as a state of complete physical,mental,and social well-being,not merely the absence of disease or infirmity.
$(1)$ Increased efficiency,$(2)$ Higher productivity,and $(3)$ Increased longevity are all positive indicators of a healthy population.
$(4)$ An increase in infant and maternal mortality rates indicates poor health infrastructure and a lack of proper healthcare,which is inconsistent with a healthy society.
Therefore,statement $(4)$ is the only one inconsistent with a healthy individual/society.