content Flashcards
what are some examples of communicable diseases?
measles
chickenpox
cholera
HIV/AIDS
what are some examples of non-communicable diseases?
cancer
high blood pressure
arthritis
diabetes
why can the presence of one disease lead to a higher susceptibility of other diseases?
- if an individual has a diseases it increases the likelihood of getting another disease.
- if the immune system has been damaged, this may increase the chance of pathogens invading the body
- if the body’s defences are damaged, this may increase the chance of pathogens getting in
- disease may stop an organ from working which may make it easier to contract another disease
what are some types of pathogen?
fungi
protists
bacteria
virus
describe the LYTIC CYCLE
- the phage latches on to a bacteria cell
- the phage injects it’s genetic material into the bacteria cell
- the phage reproduces itself within the host
- the cell ruptures allowing the phages to find free bacteria cells in the body
describe the LYSOGENIC CYCLE
- phage latches on to bacteria cell
- phage injects DNA
- phage remains combines/becomes part of the bacterial chromosome
- phage remains hidden in the cell, when the cell multiplies, the phage multiplies with them
- cell multiplies with the phage DNA and the bacterial DNA
what is a virus?
- viruses can be presented as general symptoms. i.e. headaches. colds and some of our most common illnesses are caused by. they are difficult to detect by our immune systems as viruses get inside the cells and then they are hidden.
- viruses reproduce inside cells, destroying those cells. they use cells to copy their DNA and to make more virus particles
list some physical defences of the human body
SKIN: has dry, dead outer cells are difficult for microbes to penetrate, and the sebaceous glands produce oils that help to kill microbes
NASAL HAIRS, MUCUS AND CILIA: nasal hairs keep out dust and larger microorganisms, sticky mucus traps dust and microbes which are then carried away by cilia
list some chemical defences of the human body
STOMACH ACID: the stomach contains hydrochloric acid which destroys microorganisms
TEARS: tears, saliva and mucus contain an enzyme called lysozyme which also destroys microorganisms
what are the roles of white blood cells?
- ingesting pathogens
- producing antitoxins
- producing antibodies
- memory cells
what are the advantages of immunisation?
- personal immunity
- herd immunity
what are the disadvantages of immunisation?
- discomfort
- side effects
what are the aseptic techniques used in the lab?
- all equipment must be sterilised
- inoculating loop torched through bunsen burner flame
- autoclaves to sterilise equipment in steam as this kills bacteria quickly
what are the aseptic techniques used in the core practical?
- virkon solution to wipe desk
- torch all equipment
describe the process of immunisation
- a dead or inactive pathogen is injected into the body
- our WBCs recognise special proteins on the surface of the pathogens (ANTIGENS)
- our WBCs produce antibodies
- antibodies stay in our blood (memory cells)
- if we come into contact with the pathogen again, our WBCs produce lots of antibodies very quickly. these will kill the pathogen before we become ill.
- once a lymphocyte has recognised a foreign antigen it expands to eliminate the infection
- memory cells respond very quickly to subsequent exposure to antigen
