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Earthworms belong to the phylum Annelida and play a very important role in the soil - Leaving Cert Agricultural Science - Question a - 2013
Question a
Earthworms belong to the phylum Annelida and play a very important role in the soil. (i) Give two characteristic features of the phylum Annelida. (ii) Describe any... show full transcript
Worked Solution & Example Answer:Earthworms belong to the phylum Annelida and play a very important role in the soil - Leaving Cert Agricultural Science - Question a - 2013
Step 1
Give two characteristic features of the phylum Annelida.
Answer
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Segmented Body: Annelids exhibit a segmented body structure, which allows for greater flexibility and mobility.
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Coelomate: They possess a true coelom, meaning they have a body cavity lined with mesoderm, which aids in the development of complex organ systems.
Step 2
Describe any three benefits earthworms bring to the soil.
Answer
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Improve Drainage: Earthworms create burrows in the soil, which enhances drainage and reduces waterlogging, allowing plant roots to access moisture more efficiently.
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Aeration of Soil: Their burrowing activities aerate the soil, promoting better airflow to plant roots and facilitating microbial activity that is essential for soil health.
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Decomposition of Organic Matter: Earthworms help break down organic matter, turning it into nutrient-rich humus that improves soil fertility and structure.
Step 3
Describe an investigation to estimate the earthworm population in a pasture.
Answer
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Mark Out an Area: Select a designated area (e.g., quadrant) in the pasture for your investigation.
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Random Sampling: Use quadrats to randomly assess different sections of the pasture, ensuring a representative sample is taken.
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Count Earthworms: Apply a method such as potassium permanganate solution or washing with liquid solution to bring earthworms to the surface for counting.
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Calculate Average Number: Multiply the number of earthworms counted by a factor (e.g., based on the quadrat size) to estimate the total population. For instance, if you sample 10 quadrats and count a total of 100 earthworms, you might multiply by the total area divided by the area of the quadrat to find the overall estimate.