exam questions

• What is the main reason carbon dioxide acts as a green house gas?

  • absorbs infrared radiation reflected by the surface of the earth
• Explain how studying pollen grains found in peat bogs can provide evidence of climate change (4) 

  -       Pollen is preserved in peat bogs 

  -       A plant species can be identified by its pollen- specific to plant

  -       Climate affects the type of plants growing 

  -       Depth of peat correlated with period of time since pollen was produced 

  -       Changes in pollen over time indicate changes in climate 
• What causes climate change?

  -       An increase in carbon dioxide and methane in the atmosphere that trap infrared radiation 
• Which of the following could provide evidence of climate change (1) 

  -       Dendrochronology 

  -       Peat bog pollen analysis 

  -       Ice cores
• Explain the effects of a temperature increase from 20 degrees to 30 degrees on initial rate of activity of catalase in yeast cells (3) 

  -       An increase in temperature increased the kinetic energy 

  -       More enzyme and substrate collisions

  -       More enzyme- substrate complexes forming 

  -       So increased rate of reaction
• Discuss the possible impact of climate change on the effects of leaf rust on the yield of wheat crops (4)

  •  Climate change would increase temperatures which would increase the spread of leaf rust 
  • Climate change would increase rainfall/humidity which would increase spread of leaf rust 
  • Periods of drought may decrease spread of leaf rust
  • Therefore, if leaf rust is spread, crop yield will decrease however if cold and dry and not spreading yield will not decrease.
• Explain why anthropogenic emissions of greenhouse gases are affecting the climate (3) 

  -       Burning fossil fuels releases greenhouse emissions

  -       Leading to global warming, increasing earth’s temperature

  -       Greenhouse gases trap the infrared radiation which is reflected/remitted from earth surface
• Discuss the impact of climate change on the monkey population (4) 

  -       Fewer seeds will lead to a decrease in the plant population 

  -       Fewer seeds mean there is less food/energy 

  -       Due to lipids and carbs in seed- monkeys will now not be able to generate enough heat to survive the cold winters 

  -       Monkey pop will decrease in size