Studied by 6 people
Using a scale bar, calculate the magnification of the image (2 marks)
Measure the scale bar image in mm Convert (multiply by 1000) Magnification = scale bar image length / image (written in drawing)
x660
Explain how electron micrographs such as this helped falsify the Davson-Danielli model of membrane structure (2 marks)
The Davson-Danielli model proposed two layers of protein on either side of a lipid bilayer Micrographs illustrate proteins are transmembrane proteins
Explain how the amphiphatic nature of phospholipids allows them to form bilayers (2 marks)
The outside hydrophilic parts are exposed to water Hydrophobic parts are away from water inside
Outline how O2 consumption is measured using a respirometer (2 marks)
A CO2 absorber is added A starting water level is measured Rate of movement of the bubbles is a measure of O2 consumption
Suggest one conclusion that can be drawn from the results shown in the graph (1 mark)
As fungus grows, the rate of oxygen consumption increases
Other than humidity, suggest a variable that would need to be controlled in this experiment (1 mark)
Temperature
Outline the role of fungi in nutrient cycling (2 marks)
Act as decomposers Feed on organic matter
Identify the type of blood vessels shown in the diagram (1 mark)
Veins
Deduce what the experiment demonstrated about the circulation of blood (2 marks)
Blood flows towards the heart Valves prevent backflow
Question 1 a
Davson-Danielli
Question 1 b i
Protein (V)
Question 1 b ii
Phospholipid (head)
Question 1 c i
Phospholipids on the outside
Question 1 c ii
PH values away from optimum pH
substrate does not fit in active site
1 d
Scanning electronmicrography
2 a
0.45 mm
2 b
Thymine Because thymine is not in RNA
3 a
Age and height
3 b
Both ventilation rates exercising is significantly more than at rest
Ventilation rate at 4000 m slightly higher than at sea level
3 c
Chest belt Tidal volume recorded for a given period of time
Note
Flashcard