B5 Flashcards
(21 cards)
when growing bacteria, how can you avoid contamination?
- sterilising petri dish and culture media before use
- sterilising inoculating loop in red hot flame before and after
- not fully removing lid of petri dish or placing it on desk
- securing petri dish lid in place with strips of tape to let some oxygen in- preventing dangerous anaerobic bacterial growth
- petri dish should be stored upside down to prevent condensation
- incubated at 25degrees to reduce chance of growing harmful pathogens that could survive
Measles
type: virus
symptoms: fever, rash
spread by: inhaling droplets from sneezes, coughs
prevention: vaccination, coughing and sneezing into tissues
Treatment: no cure, use painkillers
HIV
type: virus
symptoms: initially flu-like, damages immune system- causing AID, where the body can no longer fight off disease
spread by: sexual contact, sharing needles
prevention: wearing protection, not sharing needles
Treatment: no cure, but antiretroviral drugs can prevent people developing AIDS
Tobacco mosaic virus
type: virus
symptoms: creates a “mosaic” pattern of discolouration on leaves, stunting growth
spread by: contact with other plants- naturally or by farmer’s gloves
prevention: destroying infected leaves, washing infected tools/gloves
Treatment: no cure
salmonella
type: bacteria
symptoms: fever, abdominal cramps, vomiting, diarrhoea
spread by: eating food prepared unhygienically/undercooked meat
prevention: vaccinate chickens, disinfect surfaces, wash hands after touching raw meat
Treatment: antibiotics, fluids
gonorrhoea
type: bacteria
symptoms: thick yellow/green discharge, pain when urinating
spread by: sexual contact
prevention: wearing protections
Treatment: antibiotics
malaria
type: protist
symptoms: fever
spread by: spread via mosquitoes- the vector
prevention: destroying mosquito breeding grounds, mosquito nets
Treatment: antimalarial drugs
rose black spot
type: fungus
symptoms: purple/black spots on leaves, leaves turn yellow and drop off early, stunted growth
spread by: rain or wind
prevention: fungicides, destroying affected leaves
Treatment: fungicides
What does the skin do to defend humans from pathogens?
- thick, tough barrier that stops pathogens from getting into blood. Blood clots from to “plug up” cuts to skin
Name some symptoms of plant disease
- stunted growth
- decay
- malformed stems or leaves
- pests
- spots on leaves
- abnormal growth
- discolouration
how can you identify plant disease?
- referring to manuals or websites
- taking infected plants to labs
- testing kits that contain monoclonal antibodies
What are aphids?
- insects that can infect plants. they feed on the sugars in the plant’s phloem tube, causing stunted growth
Plants- physical defences
- cellulose in in plant walls acts as a barrier
- tough waxy cuticle on leaves acts as a barrier
- layers of dead cells around stem (like tree bark) fall off, taking pathogens on the surface with them
Plants- chemical defences
- plants produce antibacterial chemicals
- plants produce poisons
Plants- mechanical adaptions
- thorns, hairs
- leaves can drop or curl when touched (i.e mimosa plant)
Nitrate deficiency
symptoms: stunted growth
Explanation: plants use nitrates to make amino acids, and amino acids make proteins, which are required to build and grow plant tissue
Magnesium deficiency
symptoms: chlorosis (yellow leaves) leading to stunted growth
Explanation: magnesium needed to make chlorophyll, which is used to trap light for photosynthesis, and is what makes the leaves green
How does the nose work as a defence system?
Tiny hairs and mucus traps and stops pathogens from being breathed in
How do the teachea and bronchi work as defence systems
Sticky mucus traps pathogens we breathe in,, cilia waft the mucus and remove it from the tubes in our lungs
How does the stomach work as a defence system?
It’s very acidic and destroys most bacteria on our food
How do white blood cells fight pathogens?
- engulf them and destroy them in phagocytosis
- release antibodies which bind to the specific complementary shape
- release antitoxins
