b5 biology revision Flashcards
what’s the definition of heath
the state of mental and physical well being
what are non communicable and communicable diseases caused of
pathogens
give ways communicable diseases can be spread
-water
-air
-droplet infection
-food
- direct contact
give ways non communicable diseases can be spread
they cant be spread from one person to another
what are some examples of communicable diseases
- a flu
- influenza
-measles
-covid 19
-malaria
what are some examples of non communicable diseases
-diabetes
-depression
-obesity
-high blood pressure
what are some factors that cause ill health
-diet
-stress
-life situations (gender , amount of kids you have )
whats the definition of pathogen
microorganisms that cause disease
what are the 4 examples of pathogens
- bacteria
- viruses
- protists
- fungi
what are viruses smaller than
bacteria
how do pathogens make you feel ill
they produce toxins and attack / destroy your cells
what do you need to culture microorganisms
-you need to provide them with all the nutrients needed ( in a culture median )
- you also need warmth and oxygen
how do viruses cause cell damage
they live and reproduce inside your cells , damaging them
what nutrients do culture medians contain
-carbohydrates
-minerals
-nitrogen
-other chemicals (sometimes)
tell me the step by step culturing microorganisms
1) sterilise the inoculating loop by heating it until it turns red hot in the flame . Now let it cool but make sure to not place it down when cooling or blowing on it
2)dip the sterilised loop in a suspension of the bacteria you want to grow and use it to make zigzag streaks across the surface of the agar . Replace the lid as quickly as you can
3) fix the lid on the dish with tape to prevent microorganisms from the air contaminating the culture ( or microbes escaping ). make sure to not seal the lid all the way to ensure oxygen enters to prevent dangerous anaerobic bacteria growing
4)the petri dish should be labelled and made sure to be stored upside down so no condensation falls onto the agar surface
how do bacteria multiply
single cell division
what temperature should the cultures be stored at
25 degrees maximum
how fast does bacteria multiply
as often as 20 minutes
whats the formula for finding out the number of bacteria in the population
bacteria at the beggining of the growth period x 2 ^ number of divisions
what work did ignas semmeleweis do
found out that hygenie helped many woman survive birth
what are the ways to prevent spread of disease
- simple hygiene measures
- destroying vectors
- isolation of infected individuals
- vaccination
how does vaccination prevent disease
when individual is injected with small harmless pathogens memory cells are produced for next time
how can measles virus be spread
droplet infection
what are symptoms of measles
red skin rash and fever
