Bio 2 pathogens

pathogens

what is a pathogen

a disease causing organism

what are transmissible diseases

diseases that are caused by pathogens and can be passes from one person to another

what are trpnspimmisble diseases caused by

pathogens

what is immune response

they way in which lymphocytes respond to pathogens, producing antibodies is called the immune response

types of pathogens

parasites, viruses, bacteria, fungi, protists, prions, algae

what are the 5 groups of micro organisms

viruses, bacteria, fungi, protozoa, algae

what is malaria

a chronic, life threatening parasitic disease transmitted through a bite of a female mosquito

where is malaria more prevalent

it affects mainly poor countries as the mosquitos thrive in tropical environments

why is malaria more common in poor countries

mosquitos thrive in tropical environments

what does malaria originate from

a unicellular protozoan called plasmodium

where is plasmodium carried in a mosquito

the salivary glands of a mosquito

what are the 2 states a virus exists in

a virus(when active) and a virion(when dormant and not in contact with a host cell)

what is a viriod

an infectious RNA particle that resembles a virus but smaller

where can viruses survive

inside the cell

when can a virus reproduce

when within a living cell or when the viral nucleic acids use the host cell material to replicate

what happens after the virus leaves the host cell

the host cell is destroyed. they may swell and burst, the host cells may not be able to function properly.

what is the structure of a virus

virus is acellular. it has no nucleus, cytoplasm or organelles. viruses consist of a core od DNA or RNA but not both.

what does acellular mean

it is not a cell and has no nucleus, cytoplasm or organelles

how does the virus effect the body

the immune system becomes activated in order to fight the infection. this may lead to fever tiredness or an opportunistic disease

what is HIV

it is a viral disease. HIV aids is one of the most serious disease facing the world today.

what country has HIV infected the most

south Africa has the highest prevalence of HIV in the world. 18% of the adult population is infected with HIV

what is the full form of HIV

human immunodeficiency virus

what does HIV affect in the body

the immune system because it is specialized to infect CD4 cells, which play a significant role in immunity. Th immune is too weak to fight off diseases so the body is open to many new diseases.

physical effect of HIV

weakened immune system, resulting in fatigue, weight loss, frequent fevers and sweats, fungal infection, skin rashes, and flaky skin, diarrhoea.

what is the last stage of HIV

AIDS

what is the full form of AIDS

acquired immune deficiency syndrome

what is tuberculosis

a chronic infection

what is is tuberculosis caused by

myocardium tuberculosis(TB bacillus)

what does tuberculosis effect in the body

affects all organs, including the brain and the bones but especially the lungs.

when tuberculosis affects the lungs what is it called

pulmonary tuberculosis

what is tuberculosis spread by

by moisture droplets, it is highly contagious

what is protista

Protists are simple eukaryotic organisms that are neither plants nor animals or fungi.

characteristics of Protista

they are eukaryotic and live in moist environments

what is eukaryotic

have a true nucleus

what is the structure of fungi

they are mostly multicellular

what is athletes foot caused by

fungus called tinea

what is athletes foot

fungus that effects the skin between the toes and make the skin crack and flake

how is athletes foot treated

treated with dryness and an antifungal powder

what is the immune response by animals

first line of defence and second line of defence

what is the first line of defence in animals

the first line of defense is the skin, it prevents entry of a pathogen

what does the second line of defence involve

primary response and secondary resonse

what is the primary response of the second line of defence in immune response in animals

the primary response is to prevent pathogens from spreading by inducing inflammation or inducing fever

what is the secondary response of the second line of defence in immune response in animals

the secondary response is to activate the immune system

what does the immune system do

the destruction of the invading germs and hold memory of the response

what two group of white blood cells does the immune process involve

lymphocytes and phagocytes

what does the body do to defend ourselves from microbes

the body prevents microbes getting into the body and destroys microbes once they have got in

what are the 3 lines of defence our body has to defend against against invading microorganisms

1. non specific physical and chemical barriers
2. non specific immune system
3. specific defence system

what is the first line of defence(non specific physical and chemical barriers)

1. skin: the cells in the outer layer of the skin contain a protein called keratin
2. cillia in the trachea traps the particles in the resiperatory tract and remove them
3. ear wax has cerumen
4. saliva has lysosome that breaks down bacterial cell walls
5. stomach has mucous
6. nostrils have hairs, mucous and cilia

second line of defence non specific immune system

phagocytes(wbc) ingest and digest invading microbes thorugh a process called phagocytosis

third line of defense specific defence system

it is the adaptive immunes sytem. pathogens have chemical markers called antigens and the immune system identifies them and produces antibodies by lymphocytes(wbc) to fight the antigens.

what is a antibody

a protein that is produced by lymphocytes
(type of white blood cell) in response to the presence of a
specific antigen.

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what do antibody do

Specific antibodies bind to specific antigens and cause their destruction.

what is antibody produced by

lymphocytes

what are polyclonal antibodies

a group of antibodies

why are polyclonal antibodies formed

most microbes have more then one antigen in their surface so they stimulate more then one type pf lymphocyte resulting in the production of many different antibodies.

what happens if an antigen invades your body a second time

a
much faster response occurs which produces
much larger quantity of the required antibody.

when are memory cells formed

When activated B-cells are dividing during the
primary response, some cells stop dividing and
secreting antibody and become memory cells.

what are memory cells

After the infection has passed most b cells die, and anti body
numbers also fall off, but a small number become memory B cells. They are
ready to respond to the pathogens quickly if you meet it again.

what are t cells(t lymphocytes)

T killer
cells which destroy bacteria that have become coated with antibodies and
helper T cells, which prompt B cells to start making antibodies.

what prompts b cells to start making antibodies

T killer
cells which destroy bacteria that have become coated with antibodies and
helper T cells,

where do b cells mature in

the bone marrow

after being activated by an antigen what does the b cell proliferate into

plasma cells which secrete antibodies and memory cells which may be converted into plasma cells later

what are the 2 acquired immunities

active immunity and passive immunity

what are the 2 types of active immunity

natural active immunity and artificial active immunity

what are the 2 types of passive immunity

natural passive immunity and artificial passive immunity

what is natural active immunity

antibodies or activated lymphocytes are produced as a result of infection

what is artificial active immunity

antibodies are produced as a result of immunisation with a vaccine

natural passive immunity

antibodies are passed to a fetus through the placenta or in the colostrum

what is artificial passive immunity

antibodies that have been produced by infected host or produced in vitro are given to a healthy host

what is active immunity

defence against a pathogen by antibody production in to
the body.

what is passive immunity

short term-defence against a pathogen by antibodies
acquired from another individual, such as from mother to infant.

what does vaccine contain

A vaccine contains weakened or dead viruses or bacteria that
normally cause disease. These pathogens have same antigens as the normal
ones but they are not able to cause disease.

what is vaccination

vaccination is the method of giving antigen to stimulate the immune response through active immunization.

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what is health

a state of physical, mental , and social well being,

what are the conditions necessary for good health

goof physical and social environment

social equality and harmony

good economic conditions

what does good physical and social environment include

clean
surroundings, good sanitation, proper garbage disposal and
clean drinking water

what does good economic conditions include

job opportunities for
all for earning to have nutritious food and to lead a healthy
life.

what are the differences between healthy and disease free

what are symptoms

signs of the disease

what happens when a person is affected by a disease

the normal functioning

or the appearance of one or more systems of the body changes for the

worse.

how do physicians confirm the disease

on the basis of symptoms the physicians look for the signs of a particular disease and conduct tests to confirm the disease

what are the different types of diseases

acute disease, chronic diseases, infectious diseases, non infectious diseases.

what are acute diseases

are diseases which last only for a short period
of time and does not have long term effect on health.

examples of acute diseases

cold, cough, typhoid, cholera etc.

what is chronic disease

are diseases which lasts for a long time and
has long term drastic effect on health.

examples of chronic disease

diabetes, tuberculosis, elephantiasis, arthritis, cancer

what are infectious diseases

are

diseases which spread from an infected person to a healthy
person through air, water, food, vectors, physical contact or
sexual contact.

examples of infectious diseases

common cold, chicken pox, mumps,
measles, typhoid, cholera, tuberculosis, malaria, AIDS

what are non infectious diseases

are diseases which are not spread from an infected person to
a healthy person.

examples of non infectious disease

rickets, scurvy, night blindness, diabetes, cancer, high blood pressure

causes of disease

Diseases are caused by :-

i) Pathogens like virus, bacteria, fungi, protozoans or

worms.

ii) Poor health and under nourishment.

iii) Malfunctioning of body parts.

iv) Environmental pollution.

v) Genetic disorders.

what are infectious agents/pathogens

Viruses, Bacteria, Fungi, Protozoans
and worms.

what are pathogens

an infectious agent which cause infectious diseases

diseases from a virus

Common cold, Influenza, Measles, Mumps,
Chicken pox, AIDS, Hepatits-B etc.

diseases from bacteria

Cholera, Typhoid, Tuberculosis, Tetanus,
Anthrax, Food poisoning etc.

diseases from fungi

Skin infections.

diseases from protozoans

Malaria, Kala-azar, Amoebic dysentry,
Sleeping sickness.

diseases from worms

Intestinal infections, Elephantiasis.

what are the 2 steps of treatment

1. to reduce the effects of the disease (symptoms)


2. to kill the microbes which caused the
disease

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how do you reduce the effects of a disease

by taking medicines to bring down the
effects of the disease like fever, pain or
loose motions etc.

by taking bed rest to conserve our
energy.