Definitions [13]
Define the following.
Bacteriophages
Bacteriophages are virus that infect bacterial cells, e.g. T4 bacteriophage.
Define the following.
Prions
Viral particles which contain only protein. They do not contain nucleic acid.
Define the following:
Malnutrition
The condition of nutrition in which the food is either in inadequate quantity or in excess or it lacks in some essential nutrient is called malnutrition.
Define the following: Immunisation
Immunisation is body’s natural defence mechanism which acts by producing antibodies against the antigens infecting the body.
Define the following: Atherosclerosis
Atherosclerosis is a disease caused by the malfimtioning of heart wherein the arterial walls get hardened and thickened, reducing the flow of blood and raising the blood pressure.
Define the following: Vaccine
A vaccine is a biological preparation of a weakened or killed pathogen (disease causing microbes) which stimulates the formation of antibodies and develops immunity against a particular disease.
Define the following: Immunity
The ability of an organism to resist and overcome infection is called immunity.
What are deficiency diseases?
The diseases caused by inadequate intake of food or the lack of some essential nutrient in our diet are called deficiency diseases.
Deficiency in one or more of the nutrients causes various diseases. These are called deficiency diseases.
Define the following:
Diseases
Any disorder or abnormal working of an organ, part or system of the body leads to illness called as disease.
Define the following: Pathogen
Any organism that is capable of causing disease is called a pathogen.
Examples : bacteria, virus or other microorganism.
Define the following: Vaccination
Vaccination is a method of making the body immune to a particular disease by injecting killed or weakened disease causing microbe into a body to stimulate the formation of antibodies and develop immunity to that disease causing microbe.
Define the following:
Toxin
Toxin:
The poisonous substances secreted by pathogens that cause diseases are called toxins.
Define the following:
Vector
Vector:
Vector is an agent that acts as an intermediate carrier of the pathogen.
Key Points
- Malaria is caused by Plasmodium sp. (P. vivax, P. malariae, P. falciparum) and spreads through a female Anopheles mosquito bite.
- Sporozoites enter the human body, multiply in liver cells, then attack and rupture RBCs.
- Rupture of RBCs releases haemozoin toxin, causing chills and high fever every 3-4 days.
- Plasmodium needs two hosts - humans (asexual stage) and female Anopheles mosquitoes (sexual stage).
- Mosquito picks up gametocytes from an infected person → fertilisation in the mosquito's intestine → sporozoites reach the salivary glands → injected into the next human.
- Amoebiasis is caused by Entamoeba histolytica; houseflies transmit parasites from faeces to food/water.
- Symptoms of Amoebiasis - constipation, abdominal pain, cramps, and stools with mucous and blood clots.
- Ascariasis is caused by Ascaris and spreads through faeces-contaminated soil, water, vegetables, and fruits.
- Symptoms of Ascariasis - internal bleeding, muscular pain, fever, anaemia, and intestinal blockage.
- Filariasis is caused by Wuchereria bancrofti and W. malayi, transmitted by female Culex mosquito bite.
- Filarial worms live in the lymphatic vessels of the lower limbs, causing chronic inflammation for many years.
- Filariasis leads to deformity of limbs and genital organs due to long-term swelling.
Concepts [18]
- Bacteria
- Viruses
- Fungi
- Prions
- Useful micro-organisms
- Manifestation of Diseases
- Categories of Disease
- Harmful Microorganisms
- Airborne Diseases
- Airborne Diseases Caused by Virus
- Airborne Diseases Caused by Bacteria
- Contamination of Water and Water Borne Diseases
- Waterborne Diseases Caused by Virus
- Waterborne Diseases Caused by Bacteria
- Vector Borne Diseases
- Protozoan Diseases
- Helminthic Diseases
- Diseases Transmitted by Animals
