inquiry question 1 module 7 Flashcards
How are diseases transmitted?
definition of disease
abnormal condition which affects the bodily functions of an organism
definition of non-infectious disease
Cannot be transmitted from one person to another except from inheritance eg. cancer
definition of infectious disease
diseases that can be transmitted from one person to another not by inheritance
- caused by pathogens and are contagious
eg. covid, flu
communicable disease
animal-animal plant-plant
microbes
microorganisms that cause disease
microorganisms
anything that is small that you can’t see with an unaided eye
define pathogen
disease causing organism that are spread through vectors such as mosquitoes
- can be microscopic or macroscopic
virulence factors
enable the pathogen to inhabit its host more effectively and may even be able to evade destruction by antibiotics
types of pathogens
non-cellular: viruses, prions
unicellular: bacteria, protozoa, fungi
multicellular: fungi
infection
invasion and reproduction of a pathogen that elicits a response from the body
name pathogens
bacteria, fungi, protozoan, prion, viruses, macroparasites
bacteria
living single-celled prokaryotes
- reproduce asexually through binary fission but can also horizontally transfer genes
- Produce toxins which kill or significantly damage cells and tissues and damage cells
cell wall, cell membrane, cytoplasm, ribosomes, nucleoid, flagellum
eg. H.Pylori, tonsilitis
how are bacteria classified
by shape
cocci (spherical) - tonsilitis
bacilli (rods) - anthrax
spirilla (spiral) - syphilis
vibrio (curved) - cholera
microflora
ecosystem of bacteria and other microbes that live in or on humans
antibiotics
medications that target bacteria and kill them preventing them from multiplying
fungi
unicellular or multicellular eukaryotes
- reproduce asexually and sexually
- heterotrophic
- eg. yeasts, mould, mushrooms
- cell walls made of chitin
- Essential for the decomposition and nutrient cycling in ecosystems
- Used to produce antibiotics → makes antibacterial chemicals that are in competition with bacteria for nutrients creating an antibacterial compound
eg. ringworm, thrush
protozoa
unicellular eukaryotes
- heterotrophic organism
- Reproduce asexually through binary/multiple fission or sexually
- usually found in soil and water
- lack cell walls
survival:
become dormant cysts that can survive adverse conditions such as high temperatures, harsh chemicals and long periods without water, nutrients or oxygen
eg. giardia, malaria
heterotrophic
feed on others and do not make tier own food
protozoa classification
by locomotion
- flagella
- cilia
- pseudopods
infected animals of protozoa
carrier animals and sources of infection for susceptibel animals
eg. plasmodium lives in both human and mosquito where the first host the mosquito acts as a vector
prions
non-living non-cellular abnormally structured proteins that cause other proteins to also become abnormally structured
- Altered proteins build up and cause tissue damage and death
- cannot be easily destroyed, incurable
- long incubation period in the body
eg. scrapie, bovine spongiform encephalopathy
viruses
non-cellular non-living infectious agents
Consists of a single or double stranded RNA or DNA enclosed in a protein coat which enable it to recognise suitable host cells
- inserts their DNA or RNA into host cell
- host cell starts producing more DNA/RNA and viral proteins
-Once parts have been assembled into new viruses → burst out of cell and start infecting more cells
eg. aids, influenza, polio
macro-parasites
multicellular eukaryotic parasites that can be seen with the naked eye
endoparasites (inside) ectoparasites (outside)
eg. tapeworm, guineaworm, ticks