SIR MICHELANGELO REFALO

Transcription

1 SIR MICHELANGELO REFALO CENTRE FOR FURTHER STUDIES VICTORIA GOZO Annual Exam 2012 Subject: Env.Science Level: Intermediate Time: 2 hrs Name: 1 st year Group: Section A: Answer ALL Questions in this section. 1 a. What is ozone? (1 mark) b. What are CFCs? Briefly explain the impact of CFCs on Stratospheric ozone: c. Mention two anthropogenic activities that increase the level of CFCs in the atmosphere. (1 marks) d. In the space provided below, use simple chemical equations to show how ozone is formed and destroyed in the Earth s atmosphere. (4 marks) 1 of 12

2 e. List four negative effects associated with the destruction of the stratospheric ozone layer. 2. This question refers to the composition of the Earth s atmosphere. Fill in the following table by: a. inserting the correct terms (starting with the highest layer); and b. stating one distinguishing feature for each layer. Layer Distinguishing feature (4 marks) 3. Say whether each of the following statements are True or False by ticking the appropriate box. Give one reason for your answer. a. In the absence of greenhouse gases, the surface of the Earth would be about 35ºC colder than it is now. True False Reason: 2 of 12

3 b. The Milankovitch cycles are thought to be driving forces/patterns of natural climate change. True False Reason: c. Solar heat enters the atmosphere through the hole in the ozone layer causing global warming. True False Reason: d.global warming causes a decrease in mean sea level. True False Reason: e. Increased deforestation is contributing to global warming. True False Reason: (1.5 marks x 5) 3 of 12

4 4a. Distinguish between albedo and insolation. b. Using the space below, draw a simplified but well-annotated diagram of Earth s radiation budget. (4 marks) c. Explain in what ways, have human activity interfered with Earth s Radiation Budget. 4 of 12

5 5. The following diagram represents the Earth s layered internal structure. a. Label the diagram by filling in each box with the appropriate term. A. B. C. D. b. Give one characteristic of each layer you labelled. A._ B._ C._ D._ (2, 2 marks) 6. Water seeps into the ground and replenishes the groundwater reserves. Name the two types of aquifers found in Malta and (with reference to the different rock layers) briefly explain where they can be found. a. Name: Where found: 5 of 12

6 b. Name: Where found: 7a. Distinguish between food chain and food webs. (2, 2 marks) ( 1 marks) b. Carefully consider the diagram shown below and answer the questions that follow. i. From the diagram give an example of a; Producer; Top carnivore; Primary consumer; Secondary consumer; 6 of 12

7 ii. In the space below write down a food chain made up of 6 links. iii. Predict what would happen if all insectivorous birds were eliminated from this food web. iv. Explain why the population density of large carnivores is always very small compared to the population density of herbivores occupying the same ecosystem. (1 mark x2) 8a. What is an ecosystem? b. What are the boundaries between different ecosystems called? (1 marks) c. Is biodiversity higher or lower in these areas when compared to adjacent ecosystems? State reason. d. Ecosystems require energy to function. i. What is the original source of energy? ii. By which process do green plants capture this energy? iii. What other form of energy they convert it into? (1 mark x2) iv. Mention two ways in which organisms make use of the energy that they obtain. 7 of 12

8 v. Mention two ways in which organisms lose energy to the environment. (1, 1,1,1,1 marks) e. Most ecosystems can be visualised as a pyramid with many trophic levels and only a few individuals at the top. i. What is a trophic level? ii. Distinguish between pyramid of numbers and pyramid of biomass. iii. In the space below draw an example of an inverted pyramid of number showing 3 trophic levels. Label each trophic level. (1, 2, 2 marks) 9. Compare the climatic pattern and the type of vegetation of the following terrestrial biomes by filling the table below. Biome Climatic Pattern Type of vegetation Tundra Mediterranean Scrubland Tropical Rainforest (3 marks) 8 of 12

9 10. The following are various examples of species interactions. Write the term that best describes each interaction. a. Buffalo pecker feeding on insects found on the hide of Rhinos: b. Black walnut tree giving off chemicals and eliminating nearby plants: c. Wolfs attacking and eating deer: d. A tapeworm living in a poorly fed child in a Third World Country: e. Barnacles living on a blue whale s skin : (2.5 marks) 11. The graph below show the population growth curves of 2 different species of unicellular organisms (P.aurelia and P.caudatum). For each specie, one graph shows the growth curve obtained if the species is grown on its own, whilst another graph shows the growth curve obtained if the species is grown together with the other. a. When grown separately, both organisms show an exponential type of growth. What is exponential growth? Give a likely explanation why the unicellular organisms grow exponentially when separated from the other specie. (1 marks) 9 of 12

10 b. Describe what happens when the two species are mixed? c. What is the name and the end result of this competition? (1 mark) (1 marks) 12 a. Draw the general shapes of age structures of human populations in the following situations: i. Rapid Population Growth ii. Moderate Population Growth iii. Slow Growth (3 marks) b. Define the following terms related to factors governing population size: i. Natality: ii. iii. Mortality: Involuntary Migration: (1, 1, 1 marks) 10 of 12

11 c. List 2 reasons why the death rate in more developed countries has declined over the past years. d. Name four negative impacts human overpopulation has on the environment. (1, 2 marks) 13. Distinguish between: a. Immigration and emigration b. Pull and Push factors c. Fundamental niche and Realized niche d. Resistance and resilience of ecosystems e. Generalist specie and specialist specie (Total 5 marks) 11 of 12

12 Section B: Choose ONE question from the following; 1 a. Define Keystone Species and explain their importance in community structure and function. Give examples of Keystone species. (6 marks) b. Each year fires burn large tracts of forestland. Describe the process of succession that occurs after a forest fire destroys an existing biological community and state what this type of succession is called. (9 marks) c. Explain the concept of climax community (3 marks) d. Why does the climax community often exhibit a higher level of stability than that found in other successional stages? 2. a. Define the following terms: species, population, community, ecosystem and biome. (10 marks) b. Distinguish between biotic and abiotic factors. List two biotic and two abiotic factors that may effect a population. (2, 2, 2 marks) c. Discuss the relationship between latitudes and biomes (4 marks) 3. It is estimated that forested land the size of two football pitches is lost every second of the day from the rainforests of the world. Discuss briefly the implications of deforestation by addressing each of the environmental issues: a. the reasons behind forest destruction (4 marks) b. immediate impact of deforestation on the environment (5 marks) c. the impact of deforestation on human health (3 marks) d. the impact of deforestation on global warming and climate change (4 marks) e. any suitable corrective measures that need to be taken to overcome the negative impact of deforestation. (4 marks) 4. a. Explain the meaning of the term plate tectonics and give evidence for this phenomenon. (5 marks) b. With reference to (i) converging and (ii) diverging plate boundaries, draw a diagram (for each) illustrating the direction in which the plates move AND the sites of possible volcanic/ earthquake activity. (4, 4 marks) c. Briefly explain the occurrence of earthquakes. In your answer refer to the terms: epicentre, focus, magnitude and intensity. (5 marks) d. Explain the meaning of the term conservative plate boundaries. 5 a. Solid waste management in Malta now includes the use of engineered landfills. What are the aims and essential features required to construct and operate such waste disposal facilities? (10 marks) b. Name two possible problems encountered in the setting up a new landfill facility. c. Describe 2 advantages and 2 disadvantages of incineration over the use of engineered landfills. (8 marks) 12 of 12