8.3 3.1.4 ecosystems  (Page 4/6)

Assignment 1:

(f) Study the sketch of the forest ecosystem below:

Name the:

• producer
• primary consumer
• secondary consumer
• tertiary consumer

Primary means first.

Secondary means second.

Tertiary means the third in this case.

2. The ecosystem is the living organisms together with the ____________________________________

invisibly linked and mutually interactive.

The living part can be divided into:

(a) food producers - mainly green plants

(b) food consumers - which are macro consumers (animals which eat other organisms) or decomposers (bacteria or fungi which break up dead organisms)

Activity:

To discuss rock pool ecosystems

This ecosystem is extremely sensitive. The main factor that plays a role here is TIDES.

The tide changes twice every 24 hours. As a result of the wave action, cold,oxygen-rich sea water washes over the rock pool communities. During low tide the water in the rock pools heats up and evaporation takes place. These changescontribute to the adaptation of the organisms that live in the rock pools so that they may survive the various challenges of nature.

1. Describe what you understand by “a rock pool”.

2. List all the abiotic factors that have an impact on rock pools.

Plants in rock pools

The most common plants are sea-weeds or sea-algae. They are red, green or brown.

All contain chlorophyll but in some the green is masked by red / brown pigments. Although they are not always green, they can also produce nutrients throughphotosynthesis. Therefore they are also producers.

They also provide nutrition for a wide range of other organisms that live off them, such as mussels and some sea-snails.

1. Do research in order to describe what each of the following is:

(a) filter feeders:

(b) scavengers:

2. What would the purpose of tentacles be in sea-anemones?

3. What kind of mutual dependence exists between the organisms in a rock pool?

Assessment of the interpretation of the SKETCHES

Could you distinguish the basic rock pool components?

Environmental investigation

Brief – you are going to investigate the number of grass plants growing on the lawns of the north side and the south side of South High.

Investigate – design your investigation.

Your method must be fair, reliable, precise, valid and accurate.

You should record your results in an appropriate table.

Write up – write up your investigation.

Use the following headings –

• Hypothesis
• Method
• Justification
• Results
• Analysis
• Evaluation

Hypothesis – Write a Hypothesis for your investigation. It is a statement of your expected results (2)

Method – Write a bullet pointed Method for your investigation procedure. Remember to include the steps taken to make it Fair, Reliable, Precise andValid. (8)

Justification – Explain what you did to make your experiment Fair, Reliable, Precise and Valid. (4)

Results – Display your results in a table and in a graph if appropriate. (8)

Analysis – Use maths to analyse your results and state clearly what the results show. (4)

Evaluation - Evaluate your experiment. What was good about it and why? What could you improve and how? (6)