B6 - global challenges (from PMT) Flashcards
what tool could be used to record the abundance of different plant species in a habitat?
a quadrat
what tool could be used to record the abundance of different flying insect species in a habitat?
a sweep net
what tool could be used to record the abundance of different small crawling animal species in a habitat?
a pitfall trap
give 5 negative impacts that humans have on the environment:
-hunting
-deforestation
-pollution
-land use
-pesticides
gives 5 positive impacts that humans have on the environment:
-sustainable farming
-captive breeding programmes
-creating nature reserves
-recycling
-preserving habitats
define biodiversity
the variety in all the species living in an ecosystem
give 3 benefits to maintaining biodiversity
-ecotourism provides money for the local economy
-it can prevent extinction
-some animals or plants may have useful medicinal properties
give 2 challenges to maintaining biodiversity
-it is sometimes difficult to gain political agreement on policies
-maintaining biodiversity is expensive
how can changes in water levels affect ecosystems?
-animals may have to migrate to find water
-melting ice caps may destroy the habitats of some animals (either animals living in icy regions or by sea level rise)
how can atmospheric gases affect ecosystems?
-some organisms cannot survive when certain gases are present
-polluted water can cause illness to animals that drink it
give 5 factors that affect food security
-the human population size
-the number of pests and pathogens
-global warming and climate change
-wealthier parts of the population requiring a larger variety of food
-the high cost of farming methods
define genetic engineering?
altering the genome of an organism
how are new genes introduced into an organism?
-the organisms genes are cute using restriction enzymes to create sticky ends
-the DNA from a bacterium is also cut to produce sticky ends
-the gene is inserted into the bacteria along with an antibiotic resistance gene
-antibiotics are used to remove the bacteria that do not have the new genes
what is a transgenic organism?
an organism that contains foreign DNA
define health
a state of complete physical, mental and social well-being (as defined by the WHO)
what is a pathogen?
a microorganism that causes disease
what can HPV lead to?
HPV can lead to certain types of cervical cancer
give 5 ways diseases can be spread
-droplet infection
-eating contaminated food
-drinking contaminated water
-direct contact
-entry through wounds
give 3 ways the spread of diseases can be reduced
-visual identification of the disease
-DNA identification of the disease
-screening for antibodies associated with the disease
describe one bacterial disease that affects humans
-salmonella (food poisoning)
-transmitted by ingesting infected foods
-symptoms: fever, sickness and diarrhoea
describe one viral disease that affects humans
-human immunodeficiency virus (HIV)
-transmitted through bodily fluids and is commonly spread through sexual activities
-symptoms include: a rash and fever like symptoms
describe one fungal disease that affects humans
-athlete’s foot
-transmitted through direct contact or contact with skin particles
-symptoms include: dry and cracking skin between toes
what is the function of platelets?
platelets are small fragments of cells that are involved in blood clotting
what is the function of white blood cells?
white blood cells are involved in phagocytosis and some white blood cells produce antibodies
give 5 non specific human defences to disease
-the skin acts as a barrier
-stomach acid kills ingested pathogens
-mucus traps pathogens
-sweat contains antimicrobial chemicals
-earwax traps pathogens
how are monoclonal antibodies produced?
-antigens are injected into a mouse
-the mouse produces lymphocytes
-the lymphocytes are removed and fused with a myeloma to create a hybridoma
-the hybridoma grows rapidly and produces the antibodies
give 3 uses of monoclonal antibodies
-pregnancy tests
-detection of cancerous tissue
-drug delivery to cancer cells
what is the difference between antibiotics and antivirals?
antibiotics kill bacteria whereas antivirals inhibit the reproduction of viruses
what are antiseptics?
substances applied outside the body to kill pathogens
give 3 important steps to take when culturing microorganisms in the lab
-clean the surfaces with alcohol
-keep the culture closed until it is needed
-use a bunsen burner to sterilise equipment
what treatments are available for cardio vascular disease?
-a stent can be surgically implanted to keep arteries open
-statins can be taken to lower cholesterol levels
-pacemakers can be inserted to maintain the heart’s rhythm
-heart transplants or artificial valves can be inserted
what is cancer?
cancer is a disease where cells in the body begin to divide uncontrollably
give 2 benefits of the use of stem cells in medicine
-stem cells can be used to test new drugs
-stem cells can be used to grow new organs with no concern about rejection
give 2 risks associated with the use of stem cells in medicine
-there are ethical issues with using embryonic stem cells
-there is no guarantee how well stem cell therapies work
give one benefit and one risk of gene therapy
-benefit - it can replace faulty genes and possibly cure diseases like cystic fibrosis
-risk - the virus used to deliver the gene could cause the body harm
what is personalised medicine?
personalised medicine is preventing and treating diseases tailored specifically to a patient’s genome
what are the 4 ways a pathogen can enter an animal’s body?
-cuts in the skin
-digestive system (when food/drinks are shared)
-respiratory system (inhaling pathogens)
-reproductive system (sex)
what are the 3 ways pathogens spread between plants?
-vectors, such as insects
-direct contact of sap from an infected plant with a healthy plant
-the wind (fungal spores)
define the incubation period
the time delay between harmful microorganisms entering your body and you feeling unwell
describe how a virus replicates itself
-virus attacks cell
-inserts its genes
-tells nucleus to copy its genes
-new viruses are made
-cell bursts, releasing new viruses + destroying the cell
define the incidence of a disease
the rate at which new cases occur in a population over a period of time
name 4 ways farmers prevent the spread of disease in plants and animals
-diseased plant material burnt
-animals treated using drugs
-animals killed <3
-livestock cannot be moved
-chemical dips are installed on farms to kill pathogens on footwear
what is e.coli found in?
-raw + undercooked meat
-unpasteurised milk + dairy products
what are 4 common symptoms of food poisoning?
-stomach pains
-diarrhoea
-vomiting
-fever
name an example of a viral plant disease
tobacco mosaic virus
how does tobacco mosaic virus work?
prevents chloroplasts from forming
what is the effect of tobacco mosaic virus?
stunts growth of plant - lowers quality and quantity of crop produced
how do you prevent the spread of tobacco mosaic virus?
-infected plants should be removed
-hands + equipment washed between planting
-tobacco mosaic virus-resistant crops should be planted on previously infected areas
