Question 1

A botanist is comparing the metabolic pathways for photosynthesis in cyanobacteria and in redwood trees. What do you expect she will find?

Accepted Answer

Cyanobacteria and redwood trees both use photosynthesis to produce energy, so it is likely that they will have similar metabolic pathways for this process. However, subtle differences may exist due to differences in their cellular structures and environmental conditions. It is also possible that there may be some differences in the specific enzymes and pigments used for photosynthesis.

Question 2

Which of the following statements is TRUE regarding the carbon cycle?

Accepted Answer

The carbon cycle involves processes that cycle carbon through the Earth's ecosystems, including both long- and short-term processes. It has been a fundamental part of Earth's systems since before plants appeared, initially based on microbial processes. Therefore, all of the given statements are true regarding the carbon cycle.

Question 3

Which of the following factors likely contributed to the accumulation of O₂ within Earth's atmosphere?

Accepted Answer

All of the factors listed likely contributed to the accumulation of O₂ within Earth's atmosphere. Cyanobacteria were likely responsible for the initial increase in atmospheric oxygen, but other factors such as the cycling of oxygen during the carbon cycle, the slight decoupling between photosynthesis and respiration, and the release of O₂ as a product of photosynthesis also played a role in increasing atmospheric O₂ levels.

Question 4

A _____ takes into account the diverse interactions between primary producers, consumers, and decomposers. It does not depict the flow of carbon through an environment as being dependent on a single primary producer, consumer, and decomposer.

Accepted Answer

A food web takes into account the complex interactions between different organisms in an ecosystem, showing the interconnectedness of primary producers, consumers, and decomposers. It does not rely on a linear model of energy flow that is commonly used in food chains, which shows a single path of energy transfer from producers to top-level predators. Instead, a food web shows the multiple branching pathways of energy transfer and cycling through an ecosystem. The other answer choices do not accurately describe a food web.

Question 5

Cyanobacteria, milkweed plants, and oak trees are all considered:

Accepted Answer

Cyanobacteria, milkweed plants, and oak trees are all capable of producing their own food through photosynthesis, making them primary producers in their respective ecosystems.

Question 6

In a food web, which of these organisms converts the carbon in animal carcasses or waste back to atmospheric CO₂?

Accepted Answer

The answer of In a food web, which of these...

Question 7

Which of the following statements explains how an oxygen-rich atmosphere was possible?

Accepted Answer

An oxygen-rich atmosphere was possible because the rates of oxygen consumption (by organisms that use oxygen to break down organic molecules for energy) were lower than the rates of photosynthesis (by organisms that use sunlight to produce glucose and release oxygen as a byproduct). This allowed oxygen to accumulate in the atmosphere over time.

Question 8

Carbon moves through the ecosystem on both short- and long-term scales. Which of the following statements BEST describes the movement of carbon through short-term time scales of the food chain?

Accepted Answer

Primary producers, such as plants, fix atmospheric carbon dioxide into organic compounds through photosynthesis. These compounds are then consumed by herbivores (primary consumers) and can be further transferred to carnivores (secondary consumers). The process involves the oxidation of these compounds to release energy for the consumers.

Question 9

Decomposers are vital components of a food web because they:

Accepted Answer

Decomposers break down dead organisms and waste products, releasing carbon dioxide (CO2) back into the atmosphere as part of the carbon cycle, which is essential for maintaining the balance of carbon on Earth.

Question 10

If all of the tertiary consumers were removed from an environment, the associated food web (and thus the carbon cycle) would collapse.

Accepted Answer

While the removal of tertiary consumers may have an impact on the food web, it would not completely collapse the carbon cycle. The carbon cycle involves various processes such as photosynthesis, respiration, and decomposition that are not solely dependent on the presence of tertiary consumers.

Question 11

The diverse array of photosynthetic plants and microbes is the result of different sources of CO₂, and has little to do with environmental conditions.

Accepted Answer

The statement is false. The diversity of photosynthetic plants and microbes is largely influenced by environmental conditions, such as light intensity, temperature, availability of nutrients, and water. Additionally, the type of CO₂ utilized in photosynthesis can also differ between species and contribute to their adaptation to different environments.

Question 12

Trout and amoebas are both heterotrophs, and can inhabit similar environments (for example, a freshwater pond). However, these organisms are very different when it comes to their shape and size. Why?

Accepted Answer

Trout and amoebas differ in shape and size because they utilize different sources of organic compounds for energy. Trout are larger organisms that consume other organisms, such as small fish and insects, while amoebas are much smaller and feed on microscopic plankton and organic particles in the water.

Question 13

The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time.

Accepted Answer

The carbon cycle is closely tied to the evolution of life on Earth, as changes in the amount of carbon dioxide in the atmosphere have had major impacts on climate and the distribution of habitats for different organisms. These changes in turn have influenced the pattern of biodiversity over geological time.

Question 14

Which of the following organisms can incorporate atmospheric carbon directly into C₆H₁₂O₆, thereby playing a major role in a food web?

Accepted Answer

Primary producers, such as plants and algae, are capable of incorporating atmospheric carbon directly into organic molecules through photosynthesis. This makes them the foundation of most food webs, as other organisms rely on them for energy and nutrients.

Question 15

Examining the relationship between primary producers, primary consumers, and secondary consumers is one way to track the flow of energy _____ through a system.

Accepted Answer

Primary producers (plants) convert the energy from the sun into organic compounds through photosynthesis. Primary consumers (herbivores) consume these organic compounds for energy. Secondary consumers (carnivores) then consume the primary consumers for energy. Therefore, the flow of energy is tracked through organic compounds.

Question 16

Which of the following organisms is considered a primary consumer?

Accepted Answer

A primary consumer is an organism that feeds on producers, such as plants, and is typically herbivorous. Grasshoppers primarily eat plants, making them a primary consumer. The other options listed are not primary consumers: A) cougars are carnivores and would be considered a secondary or tertiary consumer, B) algae are producers, not consumers, D) toadstools are decomposers, and E) holly bushes are producers, not consumers.

Quiz 25: Cycling Carbon

A botanist is comparing the metabolic pathways for photosynthesis in cyanobacteria and in redwood trees. What do you expect she will find?

Which of the following statements is TRUE regarding the carbon cycle?

Which of the following factors likely contributed to the accumulation of O₂ within Earth's atmosphere?

A _____ takes into account the diverse interactions between primary producers, consumers, and decomposers. It does not depict the flow of carbon through an environment as being dependent on a single primary producer, consumer, and decomposer.

Cyanobacteria, milkweed plants, and oak trees are all considered:

In a food web, which of these organisms converts the carbon in animal carcasses or waste back to atmospheric CO₂?

Which of the following statements explains how an oxygen-rich atmosphere was possible?

Carbon moves through the ecosystem on both short- and long-term scales. Which of the following statements BEST describes the movement of carbon through short-term time scales of the food chain?

Decomposers are vital components of a food web because they:

If all of the tertiary consumers were removed from an environment, the associated food web (and thus the carbon cycle) would collapse.

The diverse array of photosynthetic plants and microbes is the result of different sources of CO₂, and has little to do with environmental conditions.

Trout and amoebas are both heterotrophs, and can inhabit similar environments (for example, a freshwater pond) . However, these organisms are very different when it comes to their shape and size. Why?

The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time.

Which of the following organisms can incorporate atmospheric carbon directly into C₆H₁₂O₆, thereby playing a major role in a food web?

Examining the relationship between primary producers, primary consumers, and secondary consumers is one way to track the flow of energy _____ through a system.

Which of the following organisms is considered a primary consumer?

Quiz 25: Cycling Carbon

A botanist is comparing the metabolic pathways for photosynthesis in cyanobacteria and in redwood trees. What do you expect she will find?

Which of the following statements is TRUE regarding the carbon cycle?

Which of the following factors likely contributed to the accumulation of O2 within Earth's atmosphere?

A _____ takes into account the diverse interactions between primary producers, consumers, and decomposers. It does not depict the flow of carbon through an environment as being dependent on a single primary producer, consumer, and decomposer.

Cyanobacteria, milkweed plants, and oak trees are all considered:

In a food web, which of these organisms converts the carbon in animal carcasses or waste back to atmospheric CO2?

Which of the following statements explains how an oxygen-rich atmosphere was possible?

Carbon moves through the ecosystem on both short- and long-term scales. Which of the following statements BEST describes the movement of carbon through short-term time scales of the food chain?

Decomposers are vital components of a food web because they:

If all of the tertiary consumers were removed from an environment, the associated food web (and thus the carbon cycle) would collapse.

The diverse array of photosynthetic plants and microbes is the result of different sources of CO2, and has little to do with environmental conditions.

Trout and amoebas are both heterotrophs, and can inhabit similar environments (for example, a freshwater pond) . However, these organisms are very different when it comes to their shape and size. Why?

The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time.

Which of the following organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in a food web?

Examining the relationship between primary producers, primary consumers, and secondary consumers is one way to track the flow of energy _____ through a system.

Which of the following organisms is considered a primary consumer?

Which of the following factors likely contributed to the accumulation of O₂ within Earth's atmosphere?

In a food web, which of these organisms converts the carbon in animal carcasses or waste back to atmospheric CO₂?

The diverse array of photosynthetic plants and microbes is the result of different sources of CO₂, and has little to do with environmental conditions.

Which of the following organisms can incorporate atmospheric carbon directly into C₆H₁₂O₆, thereby playing a major role in a food web?