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Reproduction

Small spiders look like the adults.

The spider and other arachnids in the ecosystem

Insects are adapted very well to their environment, as is the case with the spiders, scorpions and ticks; they can survive extremely dry conditions. They feed on other animals that are also hunters (not the tick, though, which is a parasite) and therefore play an important role in maintaining a balance in the ecosystem. Spiders therefore should preferably not be killed. The same is valid for scorpions, but care should be taken in the case of those with thick tails – they are poisonous to humans.

Assignment 4:

Study the following and answer the questions that follow:

The owner of a garden sprays poison on the plants in his garden to get rid of caterpillars. The gardener is unhappy about this and decides to have a look at how the poison affects other animals in the garden. Every day he counts how many spiders and flies, amongst others, he can find in the garden. He does not want to identify Animal X in the table. He notes down the numbers of creatures.

Number of animals that can be found in the garden within one hour on the indicated dates.

2 January 9 January 16 January 23 January
Spiders 20 10 7 2
Flies 2 12 24 38
Animal X 5 4 2 0

1. Explain what happened in the garden from 2 January until 23 January by referring to the numbers.

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2. What animal could Animal X possibly be? Explain why you think so.

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3. What should the owner learn from this situation?

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Assessment

Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.3: We know this when the learner evaluates data and communicates findings.

Learning Outcome 2: The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard 2.3: We know this when the learner interprets information;

Assessment Standard 2.4: We know this when the learner applies knowledge in a variation of a known situation.

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Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
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