1. Opening Questions Unit 1

2. Chi Square Test Practice A researcher wants to know if there is a different number of bat sightings a dusk(early evening) or dawn (early morning). She counts 12 bat sightings at dusk and 8 bat sightings at dawn. DF = DF = 1 Chi Critical Value = ? Chi Critical Value = 3.841 Expected values: Expected values: (12 + 8)/ 2 = 10

3. Chi Square Test Practice Categorie s ExpectedObservedO-EO-E 2 O-E 2 /E Dusk10122 Dawn1082 Total A researcher wants to know if there is a different number of bat sightings a dusk(early evening) or dawn (early morning). She counts 12 bat sightings at dusk and 8 bat sightings at dawn.

4. Chi Square Test Practice CategoriesExpectedObservedO-EO-E 2 O-E 2 /E Dusk1012240.4 Dawn108240.4 Total0.8 A researcher wants to know if there is a different number of bat sightings a dusk(early evening) or dawn (early morning). She counts 12 bat sightings at dusk and 8 bat sightings at dawn. Null Hypothesis accept

5. T- Test Practice A researcher measures the growth of plants grown with two types of fertilizers. 10 grown with fertilizer A & 11 grown with fertilizer B. DF = ? DF = 10 +11-2 =19 T Critical Value = ? T Critical Value = 2.093 T calculated value (computer calculates this based on measurements/ data values) = 1.98 Accept or Reject null hypothesis: Accept the null hypothesis. There is no significant difference between plants grown in fertilizer A & B

6. T- Test Practice A researcher measures nitrate in 5 streams near an urban area and 6 streams in a rural area DF = ? DF = 5 +6-2 =9 T Critical Value = ? T Critical Value = 2.262 T calculated value (computer calculates this based on measurements/ data values) = 2.451 Accept or Reject null hypothesis: Reject the null hypothesis. There is a significant difference between streams near urban & rural areas.

7. Question 1 What is an ecosystem? A.A species and its abiotic environment B.A community and its abiotic environment C.The habitat where a species lives D.A population of organisms in a specific habitat

8. Question 2 Explain why the carnivores in an ecosystem tend to be fewer in number and have a smaller biomass than the herbivores in the same ecosystem. ( 2 points) Energy transfer along the food chain is less than 100% efficient; For example only about 10% energy of the energy is transferred from one trophic level to another; Nutrient transfer is also less than 100% efficient; Each carnivore/ predator needs to consume many prey organisms; Because carnivore need to eat other organisms there is a tendency for size of organisms to increase as trophic level increases;

9. Explain the shape of the pyramids of energy that are constructed by ecologists to represent energy flow in an ecosystem. (3 points)

10. Energy flows up from one trophic level to the next (in a community); This energy is lost at each trophic level by waste products/feces/not all the organism is consumed; MOST energy is lost through respiration/heat; Each level on the energy pyramid is about 10%– 20% of the size of the one below it / 80%–90% energy lost between levels; A labelled diagram of pyramid of energy (indicating trophic levels and relative amounts of energy);

11. Question2 Limpets are small animals that feed on the green algae which grow on rocks on seashores. Oystercatchers (Haematopus bachmani) are birds that feed on limpets. Construct a food web to show the feeding relationship between the three species of limpets, the oystercatchers and the green algae.

12. Question 3 What does a small standard deviation signify? A.The data is not correlated. B.The data is widely spread around the mean. C.The data shows a close relationship between two variables. D.The data is clustered closely to the mean value.

13. Question 4 The t-test is used to test the statistical significance of a difference. What is that difference? A.Between observed and expected results B.Between the means of two samples C.Between the standard deviation of two samples D.Between the size of two samples

14. Question 5. What does the following scatter graph show? A.No correlation between these variables B.Strong positive correlation between these variables C.Strong negative correlation between these variables D.Weak negative correlation between these variables

15. Question 6 The diagram below shows some of the links in the carbon cycle What processes are taking place at I, II and III? I Photosynthesis II Fossilization/ deposition III. Combustion

16. Question 6 The world’s oceans can absorb large amounts of carbon dioxide. The graph shows CO2 concentrations in the atmosphere and in surface water every month, from October 1988 onwards. Describe the trends in atmospheric carbon dioxide concentration, shown in the graph. (2) Suggest two reasons for the trends that you have described. (2)

17. Question 6 Describe the trends in atmospheric carbon dioxide concentration, shown in the graph. (2) rising trend overall; annual rise and fall / fluctuations;2 Suggest two reasons for the trends that you have described. (2) (CO2 emissions from) increased burning of fossil fuels/deforestation/ other anthropogenic factor; variation in photosynthesis rates during the year / variations in CO2 uptake in the oceans;

18. Explain how the emission of gases, both naturally and through human activity, can alter the surface temperature of the Earth. (8)

19. Increase in global average temperature is called global warming; This global warming is caused by the greenhouse effect; The greenhouse effect is a natural phenomenon that has occurred over millions of years; The main gas responsible for the greenhouse effectis carbon dioxide ; Other gases like methane/nitrous oxide also cause the greenhouseeffect; The greenhouse effect is when shortwave radiation from the Sun enters atmosphere; This short wave radiation warms the surface of the Earth; This short wave radiation is reemitted as longwave radiation from the surface of the Earth; This long wave radiation is absorbed by carbon dioxide/greenhouse gases and it causes the warming of the planet; Human use of fossil fuels has increased levels of atmospheric carbon dioxide. These activities enhance the greenhouse effect ; This enhanced greenhouse effect causes rapid rise in temperatures over (approximately) hundred years; Other activities that increase greenhouse gasses and the greenhouse effect are cows/animals/peat bogs, which release methane; There are natural causes of greenhouse gases, such as the gases emitted by volcanic activity;