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