Infection and response Flashcards
Plant tissues in a leaf include:
epidermal tissues, palisade mesophyll, spongy mesophyll, xylem and phloem and stomata surrounded by guard cells
Describe roots
organs adapted (root hair cells to increase surface area) for uptake of water by osmosis and mineral ions by active transport
What do stomata and guard cells in the leaf control
gas exchange and water loss
What does the phloem do
transports dissolved sugars up and down the plant
What is translocation
movement of food molecules through phloem tissue
What does the xylem do
transports water and mineral ions from roots to leaves
What is transpiration
the loss of water at the leaves by evaporation
How are communicable diseases spread
by pathogens
What are pathogens
microorganisms that cause disease
Pathogens may be:
bacteria, viruses, fungi or protists.
How does bacteria make us feel ill
it reproduces inside the body and produces toxins
How do viruses make us feel ill
They reproduce inside cells, causing damage to the cell
Viral diseases include:
measles and HIV in animals
tobacco mosaic virus in plants
Bacterial diseases include:
salmonella and gonorrhoea
What is rose black spot disease
a fungal disease affecting plants
What causes malaria
a protist that is spread by mosquitos
Non-specific defences of the human body include:
skin - pressure, stay safe from pain
nose - chemicals, taste and smell
stomach acid - corrosive, production of mucus,
cilia - move mucus and trapped particles away from your lungs
mucus - breaks down the cell wall of bacteria
How does the immune system protect your body
uses white blood cells to destroy pathogens
White blood cells defend against pathogens by:
phagocytosis, antitoxin production and antibody production
What do vaccines contain
dead or weakened pathogens
What does vaccination prevent
illness, by causing a more rapid immune response to pathogens
How can transmission of pathogens can be reduced
immunising a large proportion of the population
What do painkillers do
treat the symptoms of illness but do not kill pathogens
Describe antibiotics
kill bacteria
do not kill viruses (virus is inside the cell)
Where have new drugs been extracted from
plants and microorganisms
The heart drug ‘Digitalis’ comes from ________
foxgloves
The pain killer ‘Aspirin’ comes from ________
willow trees
Penicillin comes from ___________
penicillium mould
New medical drugs have to be tested in ______ to check that they are _____ , _______and of the correct ________
a. trials b. safe c. effective d. dosage
Describe preclinical testing
done in the lab using cells, tissues and animals
Describe clinical trials
first done on healthy volunteers and then patients
How is bias reduced in testing for new medical drugs
placebos and double blind trials are used in clinical trials
What are monoclonal antibodies are produced from
a single cell clone
What do monoclonal antibodies specifically bind onto
one shape of antigen, so can target one type of cell or chemical inside the body
What are monoclonal antibodies are made using
mouse lymphocytes and tumour cells to make a hybridoma cells
Why are hybridoma cells cloned
to produce the same antibody that can be collected and purified
Monoclonal antibody uses include:
pregnancy tests, locating specific cells or tissues and cancer treatment
Plant diseases can be detected by:
stunted growth, spots or discolouration, decay,
growth or malformed stems and the presence of pests
What can a lack of nitrate ions lead to in plants
stunted growth
What does a lack of magnesium ions cause in plants
a lack of chlorophyl
Physical plant defence responses:
cellulose cell walls, tough waxy cuticle, layers of
dead cells (bark)
Chemical plant defence responses:
antibacterial chemicals, poisons
Mechanical adaptations for plant defence:
thorns and hairs, leaves which droop or curl, mimicry
