B7 Flashcards
Whar are some receptors for temperature in the body?
- in the skin can detect 0.5 difference in temperature
- in brain- hypothalmus - detects blood temperature
- processing centre
- if too high or low the hypothalmus triggers effectors to control the temperature
How does your body warm up?
- shivering- muscle cells contract quickly
- could be conscious decision to warm up - drink, put on clothes
go inside
How does your body cool down?
- brain stimulates body to sweat
- sweat comes ot of pores in the skin
- water molecules in sweat gain energy from the skin
- cools you down
What should you do if you are too hot or cold?
What is the function of valaves in the heart?
- they prevent blood from not moving in the heart
- like a one way door
- 2 valves
1 between each atrium and ventricle
How do cappilery beds work?
- only works due to blood being under pressure from the heart
- looses pressure when it enters the cappilery bed
- blood plasma or tissue fluid is squeezed into the bed
- surrounds cells
- diffuses to exchange oxygen and glucose with urea and carbon dioxide
- tissue with waste products leave the bed
What cools down first in the body?
- extremeities hands fingers and feet
Describe Blagden’s experiment?
- room 1 or 2 degrees above 127 celcius, went in the room
- stayed there for 8 mins
- stood in an area above 116 celcius
- walked around a bit
- felt no pain
- compression on the lungs
- anxiety
- left the room
- pulse 144
- twice the odinary heartbeat
- place an egg near the thermometer
- roasted the egg in 20 mins
What does a typical bacterial cell look like?
- one tenth of the size of animal cells
- DNA forms on circle in the cytoplasm
- no nucleus
- have extra rings of DNA called plasmids
What proteins can bacteria make?
- can only make a few proteins that humans also can
- scientists can add human genes, so bacteria can make human proteins
Whereare bacterial proteins used?
- Genetic modification(GM)
- used in insulin- made by bacteria
- youst to be extracted from pigs
- some side effects
How is genetic modification used in plants?
- used to modify plants to be resistant to herbicides
- allow farmers to kill weeds with herbicides
How are bacteria modified ?
- vector required by scientists
- plasmids used as vectors
- as they are easier to manipulate than the main DNA clump
- plasmids move in and out of cells easily
How is human insulin produced from bacteria?
- isolate the gene for human insulin and make copies of it
- make a modified plasmid that contains the human insulin gene and another gene that gives it resistance to an antibiotic
- Add the modified palsmid to a population of bacteria
- treat the population with an antibiotic
- the bacteria that survive must contain the plasmid, so they will also make insulin
- grow bacteria and harvest the insulin
- bacteriophages are viruses that can infect bacteria. scientist use them as vectors to carry larger genes into bacteria cells
What are Nematodse worms and how do they reduce crop yields?
microscopic worms in soil
- attack palnt roots
- lay eggs inside plant tissue
- kills plants
- nematicides -expensive and toxic
How are plants modified to deal with Nematode worms?
- extra cystatins are added- which affect insect’s digestive system
- already produced by plants when they are seeds
- researches used the bacteria
A grobacterium as avector to carry the extra genes
- shows high level resistance to the worms
What are the arguments for and against GM crops?
How is modern genetic profiling down?
- DNA extracted from tissue sample e.g. blood, cheek scrape
- doble strand of DNA in the sample
- DNA seperated into single strands by gentle heating
- short sections of DNA coloured with flourescent makers, the sequence of the short section is complementay to target the section of the original DNA
- Complementary DNA binds if it matches the target
- short sections of DNA are copied by multiple of PCR
- PCR products are seperated by getting electrophoesis and show up as flourescent bands
- A computer releases the gel and picks out a profile showing each band as a peak
What are some uses of genetic profiling?
- crime scenes
- family trees
- gentic disease evaluation
- used to study population of endangered animals
How are genes copied ?
- PCR(polymerase chain raection)
- allows csientists to make multiple copies of DNA
How do nanoparticles have different properties compared to to regular sized particles?
- increased surface area, without increasing volume
How do nanosilver have antibacterial properties?
- absorbrd by bacteria
- disrupt normal cell activities
- damage cells, destroy them
What are the risks of nanoparticles?
- unknown hazrd
- silver packaging, culd have environmental
damage
Whar could stem cells potentially be used for?
- skin grafts- movement of paralysed people
- repair brain damage
- Parkinsons and alzheimers
- diabetes
- possibly organ transplants
Wher do stem cells come from?
- adult stem cells come from bone marrow
- embryonic from fertilities treatments
- only early embryo’s can be used
Whar does a pacemaker do?
- control contraction of the heart
- through electrical signals
What can go wrong in the heart?
- blocked blood vessels lead to heart attacks
- valves working properly
- valve tissue may get stiff or torn
- problem with pacemaker
- irregular heartbeat
How do you replace valves in the heart?
- surgeon connect patients blood supply to a heart and lung machine
- stops the heart
- cuts open and replaces the valve
What is a disadventage of using foreign tissue to replace heart valves?
- could be rejected
- alternative artificail valve
- yet can damage blood cells
How could heart be repaired in the future?
- using stem cells
- growing pacemekers
- muscle tissue
- repair heart after attack
What is a double circulatory system?
each side of the heart has two chambers - an atrium and a ventricle
- blood enters right atrium of the heart- pumped out the right ventricle towards the lungs and becomes oxygenated
- returns to the left atrium and passes into the left ventricle
- gets harder to pump and is carried to the rest of the body
- left ventricle has thicker walls of muscle than the right
- needs more pressure to reach the rest of the body
- the right ventricle only going to the lungs
blood becomes deoxygenated
returns to the right atrium
- called double circulatory system as blood passes through the heart twice on every circuit
How does the circulatory system work?
- the haert pumps oxygenated blood to cells and organs in the body
- through the Aorta- arteries
- the depxygenated blood returns to the haert through the vena cava
- the blood is pumped through the heart into the pulmary artery to the lungs
- there the blood becomes oxygenated again and returns to the heart through the pulmary vein
What are the three types of cells floating in the plasma?
- red blood cells
- carrying oxygen
- white blood cells, platelets
- foght infection, clots wounds
What does the plasma carry?
- red and white blood cells, platelets,urea,carbon dioxide, antibodies and hormones
What are Red blood cells
- cells packed with haemoglobin
- this binds with oxygen when it passes through the lungs
- no nucleus- more for haemoglobin
- bioncave shaped cells- larger surface area to diffuse gases
- flexible to fit in capilleries
What are white blood cells and platelets ?
wb
- produce antibodies
- can digest microorganisms- phagocytosis
platelets
- made from the cytoplasm of larger cells
- send out a series of reaction which helps clotting in the blood when a person has a cut
How do you treat torn ligaments and tendons?
- ligaments symptoms
1. hear popping sound
2. bruising
3. hard to bend
4. see visible dent
tendons can be inflamed and also snap
- treat with RICE and a physiotherapist
What is a dislocation?
- when the bone slips out of the joint
What are some examples of baseline data?
- heart rate: exercise increases heart rate
- doctors recommend you train at 60% of your max. heart beat - Blood pressure: exercise increses blood pressure-120/80mm. is a healthy range
- recovery period
- fitter you are, shorter the recovery period - Proportion of body fat
- too much fat put a strain on the heart - BMI
+photo
- healthy range for adults 18.5-24.9
How do yo get accurate data?
- have good equipment- not damaged
- calibrate them regularly
- do repeats - take averages
- have repeatble results
What are some common injuries to joints?
- sprains
- dislocations
- torn ligaments
- torn tendons
How do you treat a sprain ?
syptoms1. redness and swelling
2. surface bruising3. difficulty walking
4dull, throbing ache or sharp pan
use RICE
Rest
Ice
Compression
Elevation
- after RICE massage fof two hours
What are the four functions of the skeleton?
- stores minerals such as calcium and phophorous
- makes red blood cells, platelets, and some whit blood cells in the bone marrow
- forms a system of levers with muscles attached, which allows the body to move
- protects internal organs for eg. the pelvis protects reproductive organs.
What are bones made of and how do they grow?
- made od living cells that are fed with nutrients and oxygen by the blood stream
- bones continually broken down and rebuilt
- allows children to grow
- exercise in adults can stimulate bone growth and increases bone density
Describe how a knee joint works?
How do muscles move bones?
- tendons transmit forces of the muscles
- muscles can pull at joints
- one muscle contracts to bend the joint
- the other contracts to straightens it
- called antagonistc pair
Why do sports clubs want to know your medical history and lifestyle?
- medical
- a hereditory medical conditions
- e.g. circulatory or respiratory problems - any injuries
e. g.- joint or back - medication you are taking
- inhaler
- medication you are taking
lifestyle
- healthy active lifestyle will progress faster than beginners
What are two effectors that control temperature/
- too hot
+photo
- Vasodilation- blood vessels near the surface of the skin are filled with blood
- energy from blood transfers into the environment
- cool down
too cold
+photo
Vasoconstriction
- muscles in the walls of the blood vessel control
- futher away from the skin
- less energy lost
What is type 1 diabetes?
- can be developed when young
- pancres stops makin insulin
- symptoms, thirst, lots of urine containing sugar
- too much sugar makes you drowsy
- not enough will result in a coma
- need several injection of insulin a day
- sugar level is tested daily
What is the type 2 diabetes?
- occurs in people with poor diet inactive lifestyle or who are obese- occurs during middle age usually
- body gradually stops making enough insulin or cells can’t use the insulin properly
- symptoms - thirst, frequent urination
tiredness, weight loss
overtime your arteries harden which can lead to haert attacks , kidney damage or sight problems
- type 2 need- regular moderate exercise ane need to control there sugar levels
How much energy does exercise use up?
What the benefits of exercise?
- reduces your chance of illness as your body mass is reduced
- can build friendships in groups
- can be better placed to handle the stress of life
- develop good habits
What can an unhealthy diet lead to ?
- heart disease
- obesity
- diabetes
- tooth decay
- bowel cancer
- anorexia
What are some of the lifestyle risks factors concerning cancer?
- alcohol
- increaesd chance of breast, larynx ,oesophagus,pharynx,oral cavity,liver and bowel cancer
2. processed and red meat
bowel cancer
- salt- stomach cancer
good eating habits
- fruit and veg.-decreases chance of larynx, oesophagus, oral cavity, stomach, lung cancers
- fibre-stomach cancer
- Dairy products- bowel cancer
What are Linear systems?
- a non sustainable way of living
- take-make-dump society
- can only continue for a short time
e. g. 1.fossil fuels are running out
2. natural resources are being used more quickly than they are being replaced
3. making products uses a lot of energy from fossil fuels and creates waste
5. waste can be harmful to people,wildlife and can stay in the environment for a long time
6. means rare resources are being spread thinly around the world
making they hard to reuse
What are closed loop systems?
- nature has closed loop systems
- no waste
- output from one part of the system becomes the input for another sectione.g. dead leaves- eaten by snails-feces of snails broken down by bacteria and fungi- release nitrogen and phosphorous which is taken up by plants
- a complete cycle
- natural closed loop system called an ecosytem eg. lakes woodlands and grasslands
- in an ecosystem organisma interact with the non- living elements in ther habitat
- organisms take in substances yet return them also
- no waste
What is the closed loop system for a barn owl?
What happens to Dead Organic Material(DOM)?
- worms nibble and grind leaves up in their gut with soil, leaves digested by enzymes
- fungi in the soil release digestive enzymes that break down DOM
- Dung beetles roll up feces into pellets and bury them with their eggs
- hundreds of different types of bacteria break down DOM,by breaking larger insoluble molecules(starch)into smaller molecules (glucose)
how is carbon and nitrogen transfered in an ecosystem?
Nitrogen
- taken from the air by nitrogen fixing bacteria - nitrogen- nitrates-
- nitrates used by plant yo make DNA
- one type of decomposing bacteria breaks down proteins and amino acids into ammonium ions
- other bacteria convert ammonium ions into nitrates
- in anaerobic soil, bacteria change nitrates into nitrogen gas
- anaerobic soil is waterlogged or compacted
Carbon - bacteria also break down carbohydrates in DOMeg. cellulose+ starch
- provides glucose for bacteria to respire
- release carbon dioxide
How do plants maximise their chance of being pollinated?
- make large quantities of petals and fruits
- bright colours - help attract bees
- niece smells
why do some animals produce alot of eggs and other don’t?
- lots of eggs is an insurance policy’ as many eggs won’t hatch
- mamals +birds have less of a threat to their young and produce less
Are ecosystems perfect closed loops?
- in some ways no
1. birds migrate in WInter, not all return in the Summer, material is lost
2. Rivers cary branches, and nutrienrs downstream to differenet ecosystems
3. Coral reefs grow larger as they take minerals from water
A stable ecosystem has no overall gains or losses: inputs and ouputs are balanced
Why is the water cycle out of balance in Mexico city?
- deforestation upset the natural closed loop system
- forests of the city provide rich DOM the soil and hold water like a sponge
- water drains in rivers that supply the cty during the dry season
- tree roots reduce soil erosion
- leafy branches prevent rain falling directly onto the soil
- water absorbed by trees instead of washing away soil which will go in rivers and block drains
- Water evaporation from forests canopy provides rain for the city
How do we maitain fertile soil?
- ploughing damges earthworms and compacts the soil, makes it laes fertile
- can plant rapeseed on wheat stubble soil still aerated
What happens to waste products that are non- biodegradable/
- plastic in the sea
- eaten by birds , fish and turtles
- plastic beoken up and eaten
- enters the food chain
What happens to heavy metals and chlorine in products?
-chlorine products- released dioxins when burned which are linked with cancer
heavy metals build up in ecosystems
- linked with birht defects and problems with the immune system
What is bioaccumulation?
- the build up of toxic chemicals in ecosystems
- vole eats pesticide - owl eays vole
- owl eats many voles
- eventually it dies because it has ingested to much of the pesticide
What should we do to stop bioaccumalation?
- use only biodegrable waste as it can be broken down
- e.g. cardboard instead of polystyrene
How can agriculture become a closed loop system?
- by fertilising soil with human feces and urine
- yet risks transmitting infectious diseases
- can use animal manure instead
What is Eutrophication?
- non organic fertilisers leak into ponds
- algae grows rapidly then dies
- bacteria aid in the decay od algae and remove oxygen from the water
- kills life in the pond
How do we stop Eutrophication?
- use organic fertilisers as they braek down more slowly
- crops can absorb nutrient before they reach the pond
- leave the field empty one year, so clover can fix nitrogen and fertilise the soil.
What is intensive agriculture?
- there is where large amounts of a product is grown unsustainably
- it is a linear system
- there is only one type of crop grown - more chance of disease killing trees
- pesticides kills pollinaters
- bees transported to orchards for a few weeks a year
What are some solutions for overfishing?
- setting quotas for fishing
- baning fishing of particular fish
- bluefin tuna 2010
What are some unsolved problems with fishing?
- linear fish farming
food needed, dirty water wasted
- fleets move to unprotected fishing zones
- more fish in the deep sea
- deep sea trawling damages sea bed
How can you prevent desertification?
- herds being move frequently, to prevent overgrazing
- trees are not cut down in fragile areas
- reduces soil erosion
- fallen branches and rocks
reduce erosion in stream beds
- small holes are dug and filled with decaying plant material
- provides fertile soil for seedlings
native plant species are used, as they have adapted to the harsh environments
Why should we pressure tigers in india?
- people moving away from the tigers
could provide fertile land for cattle
- tiger is a crucial, for maintaining balance in the ecosystem
- eating der so that don’t eat all the plants
- tourists come - jobs
- tigers have the rigth to live
- wrong to use tigers for medicine
What does a loss of forests cause?
-soil erosion, mud slides, settling in rivers, flash floods, loss of cloud cover, droughts
Where does oil come from?
Why is energy from oil needed to produce food?
- ploughing and planting crops
- making fertilisers and pesticides
- food processing
- transport and distribution of food
What is a sustainable way of farming?
- cultivating land with horses
- animals energy comes from biomass
- animals feces enrich the soil
- crops harvested using hand tools
- closed loop system
What is the cradle to cradle manufacturing?
- goods made from renewable materials
- toxic materials avoided
- products can be broken down into
- technical nutrients for remaking products
How are microorganisms grown?
- grown in industrial tanks called fermenters
- produce alot of toxic waste and heat
What are the benefits of using microorganisms in food production?
What do enzymes from microorganisms do during dood production?
- control flavour
- smell
- texture
- rate of production
What are some examples of microorganisms being used when makng food?
- chymosin removal from calves stomach, or grown from strains of fungus
- used when making rennet
- which is used in cheese production
How are enzymes make biofuel?
- scientists developed enzymes called lignocellulose
- breaks down lignin in plants waste into sugars, which can be used to make ethanol
- good as it uses plant waste and not crops
