Topic 3 Flashcards
(21 cards)
Explain the 4 primary animal defences
Skin defends by having top layers of dead cells which a pathogen can’t enter
Sebaceous glands produce antisocial oils to kill pathogens on the surface
The breathing system has ciliated epithelium in the bronchi and trachea which stop pathogen entering. Goblin cells produce sticky mucus which cilia waft away to be swallowed
Stomach acid kills pathogens because the pH is too low
Tears have enzymes to kill pathogens
Platelets plug exposed wounds, fibrinogen is converted to fibrin to form a mesh which red blood cells get trapped in forming a cap
Explain the two main secondary animal defences
Neutrophils engulf the pathogen as its multiloabed and digests enzymes which are broken down and destroyed
Lymphocytes produce antitoxins which are complementary to a toxin to neutralise then while a neutrophil destroys
They also recognise antigens as non-self and produce antibodies which bind and kill the pathogens or put them in a clump making them more easy to destroy
How are memory cells made
When lymphocytes have produced a complementary shape to the antigen, some remain and multiply as memory cells
How to memory cells work
They recognise the antigen on the pathogen so if reinfected they will make lots more antibodies quickly
How do vaccines work
They have the special pathogen dead or inactive in small quantities so lymphocytes can make the memory cells as the pathogen can respond more quick
What are 3 main medicine that kill pathogens
Antibiotics, antivirals and antifungals
What dose an antiviral do
Kills viruses but are specific to one pathogen only
They put holes in the cell wall weakening it on every divide until it looses its wall
Blocks a pathogen from entering a cell, preventing genetic information from being released and preventing the pathogens genetic material from being inserted
What is a blind trial
Where patients and doctors both don’t know who has a placebo but researchers do
What is a double blind trial
Patients, doctors and researches all don’t know who has a placebo
What are the 7 steps of drug testing
Preclinical testing 1 is tested on human cells grown in labs, computers and bacteria cells
Preclinical testing 2 is tested on animals
Phase 1 is tested on 100 healthy humans
Phase 2 is tested on 500 humans with disease
Phase 3 is tested on 500 to 10000 humans with disease and placebo is used
After phase 3 results are peer reviewed, published and prescribed
Phase 4 is monitoring the drug after release
How are communicable plant diseases spread and examples
Pathogens enter through natural openings: stomata, wounds, stems, roots and if aphids feed on them
Rose black spot, tobacco mosaic disease
Explain the main two noncommunicable plant diseases
Nitrate deficiency is missing NO3- which is from the soil necessary to make amino acids. Fewer proteins lead to stunted growth
Chlorosis is the lack of Mg2+ they have yellow leaves as magnesium is needed for chlorophyll and less photosynthesis can take place
How should a farmer identify plant diseases
Gardening manuals/ internet
Lab test on the plant
Monoclonal antibody tests
What are the plant physical defences
Cellulose in the cell walls is difficult for a pathogen to get through
Tough waxy cuticle
Dead cell layers in bark can’t be entered
What are the chemical defences for plants
Antimicrobials, antifungals and toxins
These deter herbivores
What are a plants mechanical defences
Thorns and hair deter animals
Leaves which drop or curl when touched scare animals
Mimicry to trick animals e.g living stones or butterfly spots
What is a virus
A small stand of DNA with a protein coat they live and reproduce inside cells
What dose a bacteria cell do
Produce poisons (toxins) that damage tissue which makes us feel ill +viruses reproduce inside our cells causing damage making you feel ill
How are monoclonal antibodies produced in steps
A mouse is injected with an antigen stimulating the lymphocytes to make the complementary antibodies
The antibodies are specific and don’t divide so are added to tumour cells which can divide indefinitely resulting in hybridoma cell which can divide and make antibodies
The hybridoma cells divide by mitosis to form clones which are all the same
The antibodies are purified and collected
What the main 3 things monoclonal antibodies used for
Medical diagnosis e.g pregnancy test
Treatment of cancers or autoimmune diseases as they can target specific cells
Laboratory research
How dose a pregnancy test work in 6 steps
Urine gose on the test strip
Urine moves up the test strip by capillary action
It reaches a test strip containing mobile monoclonal antibodies (with a Color marker) which will bind to the human chorionic gonadotropin
Further along there is a line of immobilised antibodies also binding to hcg
All three things present cause the test kind to change colour
A second set of immobilised antibodies will catch any left mobile antibodies always changing colour A second-the control line
