8.2 3.1.3 environment  (Page 6/8)

ANALYSIS

NB- Come back and use South African examples for the model answer examples

Examine the data you collected when making your ABC profile. Use your collected data to answer the following questions.

1. What effect does the environment (abiotic) have on the organisms (biotic) living there? Give FIVE specific examples from your profile. [For example: Lily pads (biotic) are able to grow in my area because it is a natural wetland that has standing, stagnant water (abiotic) all year long.]

2. What effect do the organisms (biotic) have on the environment (abiotic)? Give THREE specific examples from your profile. [For example: The area is heavily shaded by spruce trees (biotic). The shade keeps the soil moist (abiotic) and reduces the air temperature.]

3. How do natural forces affect the area? Give ONE specific example from your profile. Consider the direction of the prevailing winds, the direction from which the sun’s rays come, gravity (if you are on a slope), etc…

4. How have humans affected your area? Give ONE specific example.

5. Predict how your area would change if the amount of rainfall doubled. Be sure to mention how this increase in rainfall would affect the abiotic and bioticfactors.

Questions

Question 1

Read the following text and answer the questions that follow :

South Africa has offered to slow the growth of its greenhouse gas emissions by 34% by 2020. The biggest producers of greenhouse gases in South Africa areEskom, the producers of electricity, and Sasol, the producers of petrol and diesel from fossil fuels.

1.1.Which is the most important greenhouse gas?(1)

1.2.Explain why Eskom and Sasol produce the most greenhouse gases. (2)

1.3.You are a scientist who has been employed by the government to check that the target is reached. Briefly explain the methodology you would use to dothis. (3)

1.4.Suggest two strategies that Eskom and Sasol could use to reduce their greenhouse gas emissions. (2)

Question 2

Study the table below on ozone depletion and answer the questions that follow:

Amount of ozone depletion of stratosphere between 1982&1996

2.1.Comment on the ozone depletion during the period 1982 to 1996.(2)

2.2.How much of the ozone was lost from the stratosphere in 1990? (1)

2.3.CFC's can stay around for about 100 years. What is the implication of this for the ozone layer? (1)

2.4.Give ONE possible reason for the decrease in ozone depletion after 1994.(2)

Question 3

The dying of trees due to acid rain is brought about by changes in the pH of thesoil. Tshepo observed that trees in his town were gradually dying. He decided to investigate the effect of acid rain on germinating bean seeds. He did thefollowing:

• Placed cotton wool on 6 saucers
• Poured a solution with a different pH (varying from pH 2 to pH 7) onto the cotton wool in each saucer
• Placed 50 bean seeds onto the cotton wool in each saucer
• Covered the seeds and left them on the shelf for a week
• The following results were obtained: