Pyramids Worksheet - Free Printable

I will solve the problems presented in the image by analyzing each of the three ecological pyramids shown. I'll answer each question based on the visual information and my knowledge of ecology.

First, look closely: The image contains three distinct ecological pyramids, each with a set of questions.

1. Top Pyramid (Pyramid of Numbers): This is a classic inverted pyramid shape with organisms drawn at each level. From bottom to top: grasses, insects, frogs, snakes, and an eagle at the very top.
2. Middle Pyramid (Pyramid of Biomass - Terrestrial): This pyramid shows a human at the top, followed by cattle, then grasses. It has a wide base and narrows towards the top.
3. Bottom Pyramid (Pyramid of Energy): This is a bar chart showing energy values in kilojoules (kJ) for different trophic levels: Sun → Producer (Sunflower) → Primary Consumer (Beetle) → Secondary Consumer (Mouse) → Tertiary Consumer (Owl).

Now, I will address each numbered question one by one.

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Question 1: How many trophic levels are in this pyramid?

- First, look closely: Looking at the top pyramid, I can count the distinct layers of organisms.
- Level 1: Grasses (Producers)
- Level 2: Insects (Primary Consumers)
- Level 3: Frogs (Secondary Consumers)
- Level 4: Snakes (Tertiary Consumers)
- Level 5: Eagle (Quaternary Consumer)
- Conclusion: There are 5 trophic levels.

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Question 2: What is the top consumer?

- First, look closely: The organism at the apex (top) of the first pyramid is an eagle.
- Conclusion: The top consumer is the eagle.

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Question 3: Is this an energy, number or biomass pyramid?

- First, look closely: This pyramid shows individual organisms (a few grasses, more insects, fewer frogs, even fewer snakes, and one eagle). The width of each level represents the *number* of individuals, not their mass or energy content. This is characteristic of a Pyramid of Numbers.
- Conclusion: This is a Pyramid of Numbers.

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Question 4: How many trophic levels are in this pyramid?

- First, look closely: Looking at the middle pyramid, I can count the distinct layers.
- Level 1: Grasses (Producers)
- Level 2: Cattle (Primary Consumers)
- Level 3: Human (Secondary Consumer)
- Conclusion: There are 3 trophic levels.

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Question 5: What is 1st consumer that is seen?

- First, look closely: The organism in the level directly above the producers (grasses) is the cattle.
- Conclusion: The first consumer is the cattle.

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Question 6: Is this an energy, number or biomass pyramid?

- First, look closely: This pyramid depicts the *biomass* (total mass of living material) at each trophic level. In a terrestrial ecosystem, the biomass of producers (grasses) is much larger than the biomass of the primary consumers (cattle), which is in turn larger than the secondary consumers (humans). The shape reflects the total dry weight or mass of organisms at each level.
- Conclusion: This is a Pyramid of Biomass.

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Question 7: How many trophic levels are in this pyramid?

- First, look closely: Looking at the bottom pyramid, I can count the distinct energy levels.
- Level 1: Sun (Energy Source)
- Level 2: Sunflower (Producer)
- Level 3: Beetle (Primary Consumer)
- Level 4: Mouse (Secondary Consumer)
- Level 5: Owl (Tertiary Consumer)
- Note: While the sun is the source, the trophic levels typically start with the producer. So we have:
- Trophic Level 1: Sunflower
- Trophic Level 2: Beetle
- Trophic Level 3: Mouse
- Trophic Level 4: Owl
- Conclusion: There are 4 trophic levels.

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Question 8: Does this follow the 10% law if applied? Why?

- First, look closely: The pyramid provides specific energy values:
- Producer (Sunflower): 10,000 kJ
- Primary Consumer (Beetle): 1,000 kJ
- Secondary Consumer (Mouse): 100 kJ
- Tertiary Consumer (Owl): 10 kJ
- Next, find information: The "10% Law" (or Lindeman's Law) states that only about 10% of the energy from one trophic level is transferred to the next.
- Then, review the findings: Let's check the math:
- From Producer to Primary Consumer: (1,000 kJ / 10,000 kJ) * 100 = 10%
- From Primary to Secondary: (100 kJ / 1,000 kJ) * 100 = 10%
- From Secondary to Tertiary: (10 kJ / 100 kJ) * 100 = 10%
- Conclusion: Yes, this pyramid follows the 10% law perfectly. Each level receives exactly 10% of the energy from the level below it, which is a standard representation used to illustrate this ecological principle.

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Question 9: Will all the organisms survive? Explain.

- First, look closely: This question relates to the energy pyramid. The owl at the top has only 10 kJ of energy available.
- Next, find information: In ecology, the survival of organisms at higher trophic levels is dependent on sufficient energy flow from lower levels. A very small amount of energy at the top means there can only be a small population of top predators.
- Then, review the findings: While the pyramid illustrates the energy transfer, it doesn't guarantee survival. In reality, the 10 kJ might be enough to sustain one or a few owls, but any disruption (like a decrease in mouse population) could lead to starvation. The pyramid shows the theoretical maximum sustainable population based on energy, not the actual survival outcome.
- Conclusion: Not necessarily. While the energy values follow the 10% rule, the survival of all organisms depends on other factors like predation, disease, and environmental conditions. The low energy at the top (10 kJ for the owl) means that only a very small number of owls can be supported by this system. If the population of owls exceeds what the 10 kJ can sustain, they will not all survive.

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Question 10: Is this an energy, number or biomass pyramid?

- First, look closely: This pyramid is explicitly labeled with units of energy (kJ) and shows the flow of energy from the sun through the food chain. The bars represent the amount of energy available at each trophic level.
- Conclusion: This is an Energy Pyramid.

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## Final Answer

Here are the answers to all the questions based on the analysis of the three ecological pyramids:

1. How many trophic levels are in this pyramid? There are 5 trophic levels.
2. What is the top consumer? The top consumer is the eagle.
3. Is this an energy, number or biomass pyramid? This is a Pyramid of Numbers.
4. How many trophic levels are in this pyramid? There are 3 trophic levels.
5. What is 1st consumer that is seen? The first consumer is the cattle.
6. Is this an energy, number or biomass pyramid? This is a Pyramid of Biomass.
7. How many trophic levels are in this pyramid? There are 4 trophic levels (starting from the producer).
8. Does this follow the 10% law if applied? Why? Yes, it follows the 10% law. Each trophic level receives exactly 10% of the energy from the level below it (10,000 kJ → 1,000 kJ → 100 kJ → 10 kJ).
9. Will all the organisms survive? Explain. Not necessarily. While the energy values follow the 10% rule, survival depends on other ecological factors. The very low energy at the top (10 kJ for the owl) can only support a very small population. If the owl population is too large, not all individuals will survive due to insufficient energy.
10. Is this an energy, number or biomass pyramid? This is an Energy Pyramid.