B6 - global challenges (from PMT)

Question 1

what tool could be used to record the abundance of different plant species in a habitat?

Answer 1

a quadrat

Question 2

what tool could be used to record the abundance of different flying insect species in a habitat?

Answer 2

a sweep net

Question 3

what tool could be used to record the abundance of different small crawling animal species in a habitat?

Answer 3

a pitfall trap

Question 4

give 5 negative impacts that humans have on the environment:

Answer 4

-hunting
-deforestation
-pollution
-land use
-pesticides

Question 5

gives 5 positive impacts that humans have on the environment:

Answer 5

-sustainable farming
-captive breeding programmes
-creating nature reserves
-recycling
-preserving habitats

Question 6

define biodiversity

Answer 6

the variety in all the species living in an ecosystem

Question 7

give 3 benefits to maintaining biodiversity

Answer 7

-ecotourism provides money for the local economy
-it can prevent extinction
-some animals or plants may have useful medicinal properties

Question 8

give 2 challenges to maintaining biodiversity

Answer 8

-it is sometimes difficult to gain political agreement on policies
-maintaining biodiversity is expensive

Question 9

how can changes in water levels affect ecosystems?

Answer 9

-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)

Question 10

how can atmospheric gases affect ecosystems?

Answer 10

-some organisms cannot survive when certain gases are present
-polluted water can cause illness to animals that drink it

Question 11

give 5 factors that affect food security

Answer 11

-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

Question 12

define genetic engineering?

Answer 12

altering the genome of an organism

Question 13

how are new genes introduced into an organism?

Answer 13

-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

Question 14

what is a transgenic organism?

Answer 14

an organism that contains foreign DNA

Question 15

define health

Answer 15

a state of complete physical, mental and social well-being (as defined by the WHO)

Question 16

what is a pathogen?

Answer 16

a microorganism that causes disease

Question 17

what can HPV lead to?

Answer 17

HPV can lead to certain types of cervical cancer

Question 18

give 5 ways diseases can be spread

Answer 18

-droplet infection
-eating contaminated food
-drinking contaminated water
-direct contact
-entry through wounds

Question 19

give 3 ways the spread of diseases can be reduced

Answer 19

-visual identification of the disease
-DNA identification of the disease
-screening for antibodies associated with the disease

Question 20

describe one bacterial disease that affects humans

Answer 20

-salmonella (food poisoning)
-transmitted by ingesting infected foods
-symptoms: fever, sickness and diarrhoea

Question 21

describe one viral disease that affects humans

Answer 21

-human immunodeficiency virus (HIV)
-transmitted through bodily fluids and is commonly spread through sexual activities
-symptoms include: a rash and fever like symptoms

Question 22

describe one fungal disease that affects humans

Answer 22

-athlete’s foot
-transmitted through direct contact or contact with skin particles
-symptoms include: dry and cracking skin between toes

Question 23

what is the function of platelets?

Answer 23

platelets are small fragments of cells that are involved in blood clotting

Question 24

what is the function of white blood cells?

Answer 24

white blood cells are involved in phagocytosis and some white blood cells produce antibodies

Question 25

give 5 non specific human defences to disease

Answer 25

-the skin acts as a barrier
-stomach acid kills ingested pathogens
-mucus traps pathogens
-sweat contains antimicrobial chemicals
-earwax traps pathogens

Question 26

how are monoclonal antibodies produced?

Answer 26

-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

Question 27

give 3 uses of monoclonal antibodies

Answer 27

-pregnancy tests
-detection of cancerous tissue
-drug delivery to cancer cells

Question 28

what is the difference between antibiotics and antivirals?

Answer 28

antibiotics kill bacteria whereas antivirals inhibit the reproduction of viruses

Question 29

what are antiseptics?

Answer 29

substances applied outside the body to kill pathogens

Question 30

give 3 important steps to take when culturing microorganisms in the lab

Answer 30

-clean the surfaces with alcohol
-keep the culture closed until it is needed
-use a bunsen burner to sterilise equipment

Question 31

what treatments are available for cardio vascular disease?

Answer 31

-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

Question 32

what is cancer?

Answer 32

cancer is a disease where cells in the body begin to divide uncontrollably

Question 33

give 2 benefits of the use of stem cells in medicine

Answer 33

-stem cells can be used to test new drugs
-stem cells can be used to grow new organs with no concern about rejection

Question 34

give 2 risks associated with the use of stem cells in medicine

Answer 34

-there are ethical issues with using embryonic stem cells
-there is no guarantee how well stem cell therapies work

Question 35

give one benefit and one risk of gene therapy

Answer 35

-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

Question 36

what is personalised medicine?

Answer 36

personalised medicine is preventing and treating diseases tailored specifically to a patient’s genome