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10. (a) (i) What is a pyramid of numbers? (ii) Using organisms from the ecosystem that you have investigated draw a pyramid of numbers to show at least three trophic (feeding) levels - Leaving Cert Biology - Question 10 - 2006
Question 10
10. (a) (i) What is a pyramid of numbers? (ii) Using organisms from the ecosystem that you have investigated draw a pyramid of numbers to show at least three trophic... show full transcript
Worked Solution & Example Answer:10. (a) (i) What is a pyramid of numbers? (ii) Using organisms from the ecosystem that you have investigated draw a pyramid of numbers to show at least three trophic (feeding) levels - Leaving Cert Biology - Question 10 - 2006
Step 1
What is a pyramid of numbers?
Answer
A pyramid of numbers is a graphical representation that shows the number of organisms at each trophic level in an ecosystem. The base of the pyramid represents the producers, followed by primary consumers, secondary consumers, and so forth. Typically, the number of individuals decreases as you move up the trophic levels due to energy loss at each level.
Step 2
Using organisms from the ecosystem that you have investigated draw a pyramid of numbers to show at least three trophic (feeding) levels.
Answer
To illustrate a pyramid of numbers, consider an ecosystem with the following organisms:
- Producers: 1000 plants
- Primary Consumers: 100 herbivores (e.g., grasshoppers)
- Secondary Consumers: 10 carnivores (e.g., birds that feed on the herbivores)
The pyramid would have the producers at the bottom (1000), above them the primary consumers (100), and then the secondary consumers (10) at the top, resembling a triangular shape.
Step 3
What does the graph tell you about the number of thrushes?
Answer
The graph shows a fluctuating trend in the number of thrushes throughout the year, with peaks during the months of May and June. This indicates that the thrush population increases significantly during the breeding season, likely due to reproductive factors and the availability of food.
Step 4
Step 5
Suggest two reasons for the change in the number of thrushes at B.
Answer
- Seasonal decline in food resources as the breeding season ends, leading to increased competition among thrushes for limited food.
- Environmental factors such as cooler temperatures or changes in habitat that may cause stresses, reducing the survival rates of fledglings.
Step 6
Would you expect similar changes in numbers for other small birds in the wood? Explain your answer.
Answer
Yes, it is likely that other small birds in the wood would show similar changes in population numbers. Like thrushes, many small birds depend on seasonal food availability and their breeding cycles, which also influence their population dynamics.
Step 7
Waste management is becoming an increasingly difficult matter. Suggest two reasons for this.
Answer
- Increasing population growth leads to higher waste generation, overstretching existing waste management systems.
- Rising consumerism and disposable culture contribute to greater quantities of waste, making it challenging to manage effectively.
Step 8
Describe one method of waste management by reference to agriculture, fisheries or forestry.
Answer
One method of waste management in agriculture is the use of organic waste recycling through composting. Farm residues such as crop leftovers and livestock manure can be composted to create organic fertilizers, which improve soil fertility while reducing waste.
Step 9
Suggest some ways of minimizing waste.
Answer
- Reduce: Limit unnecessary purchases and opt for products with minimal packaging.
- Reuse: Find new uses for items instead of discarding them.
- Recycle: Commit to using recycling programs for paper, plastics, and metals.
- Compost organic waste to reduce landfill impact.