Biology May 2023 1H Flashcards
Tissue
A group of the same cells
Type of tissue in plants that contain stem cells
Meristem tissue
Which plant does aspirin originate from
Willow
Suggest one reason why berries are used instead of leaves or roots
Berries easy to access/pick
Calulate mass of chemical A in 200g of the leaves with chlorosis
0.6 x 1.2 = 0.72
0.72 x 2 = 1.44
1.44 x 1000 = 1440
One reason why leaves of deadly nightshade plant have chlorosis
Lack of chlorophyll
2 reasom why it’s important for drugs to be tested in clinical trials before drugs approved for use by the public
To check toxicity
To check dosage
Suggest 1 reason why a report making claims about effects of chemical A may be biased
Writers, companies may get financial gain
How can scientists be sure that claims about new drugs are valid
Have the claims peer reviewed
Which part of the heart recieves oxygenated blood from the lungs
A
Which part of the heart pumps deoxygenates blood to the lungs
C
Where in the heart is the pacemaker found
Right atrium
Describe 2 ways the structure of an artery is different from the structure of a vein
Artery has thicker muscle
Artery doesn’t contain valves
Predict blood flow in coronary artery with 35% blockage
18 to 24
Explain the effect of a partly blocked coronary artery on the human body
Reduced blood flow to heart
Less oxygen and glucose to heart
Less aerobic respiration and more anaerobic respiration
Less energy released
Less muscle contraction so less blood around body
Explain how 1 treatment for a blockage in a coronary artery works
Stent to open artery
How does salmonella bacteria in food cause symptoms of vomiting and diarrhoea
Bacteria release toxins
How immune systems of animals repond to vaccination
White blood cells produce antibodies
Antibodies are specific correct to slamonella
Antibodies bind to salmnoella
No bacteria salmonella eaten
Number of bacteria never reaches high enough level for infection to develop
Fewer toxins produced
Describe 2 aseptic techniques scientists should have used in investigation
Disinfect hands
Sterilise petri dish
Why scientists use 37°C but stidents use 25°C to incubate bacteria
37°C is human body temperature
Salmonella grows better at 37°C
25°C prevents growth of bacteria harmful to students
What is the purpose of the paper disc with no antibiotic
Act as a control
Why should antibiotic A or antibiotic B be prescribed
They killed the most bacteria
How results in figure 4 could be used to obtain a quantitative comparison of antibiotcs A and B
Measure radius of each clear area
Suggest why antibiotic B no longer had an effect
Bacteria must be resistant
