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10. (a) Using organisms from the ecosystem you have studied, draw a pyramid of numbers to show at least three feeding levels - Leaving Cert Biology - Question 10 - 2012
Question 10
10. (a) Using organisms from the ecosystem you have studied, draw a pyramid of numbers to show at least three feeding levels. (b) (i) All organisms in an ecosystem ... show full transcript
Worked Solution & Example Answer:10. (a) Using organisms from the ecosystem you have studied, draw a pyramid of numbers to show at least three feeding levels - Leaving Cert Biology - Question 10 - 2012
Step 1
(b) (i) Explain the underlined words.
Answer
Biotic factors refer to the activities and interactions of living organisms within an ecosystem, such as predation, competition, and symbiosis. These factors influence organism behavior and population dynamics. In contrast, abiotic factors pertain to the non-living components of the environment, such as temperature, sunlight, pH level, and moisture, which can affect how organisms survive and thrive.
Step 2
(b) (ii) Name any two abiotic factors from an ecosystem you have studied and describe how you measured each one.
Answer
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Temperature: I measured the temperature using a thermometer. I took readings at different times of the day to monitor fluctuations.
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Soil pH: I measured the soil pH using a pH meter. This involved collecting soil samples and following the pH meter's instructions to ensure accurate readings.
Step 3
(b) (iii) Use the following key to identify animals A, B and C.
Answer
A is identified as a Planarian based on its flat body and two eye spots as described in the key. B is identified as a Nematode due to its rounded body shape. C is identified as a Trilobium because it has three pairs of legs, as indicated in the identification key.
Step 4
Step 5
(c) Distinguish between a quantitative and a qualitative survey.
Answer
A quantitative survey collects numerical data, such as counting the number of individuals of a species present in a specific area. A qualitative survey, on the other hand, focuses on the variety of organisms present, documenting the species and their characteristics without quantification.
Step 7
(c) (ii) Describe how you carried out a quantitative survey to determine its frequency.
Answer
To carry out a quantitative survey, I used a quadrat method. I threw a quadrat randomly several times in the area and counted the number of daisies within each quadrat, then calculated the average density.
Step 8
(c) (iii) Suggest how plants and/or animal numbers increase and/or decrease.
Answer
The disappearance of a species can lead to an increase in the population of its competitors, as there would be less competition for resources. Conversely, the loss of a primary producer can diminish herbivore numbers due to a lack of food, subsequently affecting carnivore populations reliant on those herbivores.