Energy Flow And Matter Cycles - Reading - Quiz, Flashcards & Trivia

1. Autotrophs use environmental (inorganic) energy to build complex (organic) molecules from simple compounds.

True

False

Autotrophs, such as plants and some bacteria, are able to use inorganic energy sources, such as sunlight or chemical reactions, to convert simple compounds into complex organic molecules through a process called photosynthesis or chemosynthesis. This allows them to produce their own food and energy, making the statement "Autotrophs use environmental (inorganic) energy to build complex (organic) molecules from simple compounds" true.

Explanation

Autotrophs, such as plants and some bacteria, are able to use inorganic energy sources, such as sunlight or chemical reactions, to convert simple compounds into complex organic molecules through a process called photosynthesis or chemosynthesis. This allows them to produce their own food and energy, making the statement "Autotrophs use environmental (inorganic) energy to build complex (organic) molecules from simple compounds" true.

2. 50% of available energy is transferred from one trophic level to the next.

True

False

The statement is incorrect. Only about 10% of available energy is transferred from one trophic level to the next. This is because energy is lost as heat during metabolic processes and is also used by organisms for their own growth and maintenance. Therefore, the amount of energy available decreases as it moves up the food chain.

Explanation

The statement is incorrect. Only about 10% of available energy is transferred from one trophic level to the next. This is because energy is lost as heat during metabolic processes and is also used by organisms for their own growth and maintenance. Therefore, the amount of energy available decreases as it moves up the food chain.

3. Matter is recycled in an ecosystem.

True

False

In an ecosystem, matter is constantly recycled through various processes such as decomposition, nutrient cycling, and energy transfer. When organisms die, their bodies decompose, releasing nutrients back into the environment. These nutrients are then taken up by other organisms, continuing the cycle. Additionally, through processes like photosynthesis and respiration, matter is transformed and exchanged between living organisms and the environment. Therefore, it is true that matter is recycled in an ecosystem.

Explanation

In an ecosystem, matter is constantly recycled through various processes such as decomposition, nutrient cycling, and energy transfer. When organisms die, their bodies decompose, releasing nutrients back into the environment. These nutrients are then taken up by other organisms, continuing the cycle. Additionally, through processes like photosynthesis and respiration, matter is transformed and exchanged between living organisms and the environment. Therefore, it is true that matter is recycled in an ecosystem.

4. Water can enter the atmosphere by evaporating from plant leaves.

True

False

Plants have tiny openings on their leaves called stomata, which allow water to evaporate from the plant's tissues into the surrounding air. This process is known as transpiration. As water evaporates from the leaves, it enters the atmosphere as water vapor. Therefore, it is true that water can enter the atmosphere by evaporating from plant leaves.

Explanation

Plants have tiny openings on their leaves called stomata, which allow water to evaporate from the plant's tissues into the surrounding air. This process is known as transpiration. As water evaporates from the leaves, it enters the atmosphere as water vapor. Therefore, it is true that water can enter the atmosphere by evaporating from plant leaves.

5. Nitrogen makes up 78% of the atmosphere.

True

False

Nitrogen is the most abundant gas in the Earth's atmosphere, making up approximately 78% of it. This means that out of all the gases present in the atmosphere, nitrogen constitutes the largest portion.

Explanation

Nitrogen is the most abundant gas in the Earth's atmosphere, making up approximately 78% of it. This means that out of all the gases present in the atmosphere, nitrogen constitutes the largest portion.

6. Sugar is the main energy source for life.

True

False

The statement "Sugar is the main energy source for life" is false. While sugar, or glucose, is an important source of energy for many organisms, it is not the only source. Other molecules such as fats and proteins can also be broken down to release energy. Additionally, some organisms, like certain bacteria, can obtain energy from inorganic substances through processes like chemosynthesis. Therefore, while sugar is an important energy source, it is not the sole or main source for all forms of life.

Explanation

The statement "Sugar is the main energy source for life" is false. While sugar, or glucose, is an important source of energy for many organisms, it is not the only source. Other molecules such as fats and proteins can also be broken down to release energy. Additionally, some organisms, like certain bacteria, can obtain energy from inorganic substances through processes like chemosynthesis. Therefore, while sugar is an important energy source, it is not the sole or main source for all forms of life.

7. All heterotrophs eat animals for energy.

True

False

The statement "All heterotrophs eat animals for energy" is false because heterotrophs include not only animals, but also fungi and many types of bacteria. While animals do consume other organisms for energy, there are many heterotrophs that obtain energy by consuming non-animal sources such as plants, algae, or decaying organic matter. Therefore, it is incorrect to say that all heterotrophs eat animals for energy.

Explanation

The statement "All heterotrophs eat animals for energy" is false because heterotrophs include not only animals, but also fungi and many types of bacteria. While animals do consume other organisms for energy, there are many heterotrophs that obtain energy by consuming non-animal sources such as plants, algae, or decaying organic matter. Therefore, it is incorrect to say that all heterotrophs eat animals for energy.

8. All producers use photosynthesis.

True

False

The statement "All producers use photosynthesis" is not true. While it is true that many producers, such as plants, algae, and some bacteria, use photosynthesis to convert sunlight into energy, there are also other types of producers that do not rely on photosynthesis. For example, some bacteria and archaea can obtain energy through chemosynthesis, which does not involve sunlight. Therefore, the statement is false.

Explanation

The statement "All producers use photosynthesis" is not true. While it is true that many producers, such as plants, algae, and some bacteria, use photosynthesis to convert sunlight into energy, there are also other types of producers that do not rely on photosynthesis. For example, some bacteria and archaea can obtain energy through chemosynthesis, which does not involve sunlight. Therefore, the statement is false.

9. Plants release carbon dioxide, while animals breathe in carbon dioxide.

True

False

Plants actually release oxygen through a process called photosynthesis, not carbon dioxide. Animals, on the other hand, release carbon dioxide as a waste product of respiration. Therefore, the statement that plants release carbon dioxide and animals breathe in carbon dioxide is incorrect.

Explanation

Plants actually release oxygen through a process called photosynthesis, not carbon dioxide. Animals, on the other hand, release carbon dioxide as a waste product of respiration. Therefore, the statement that plants release carbon dioxide and animals breathe in carbon dioxide is incorrect.

10. Energy cycles through an ecosystem.

True

False

In an ecosystem, energy does not cycle but flows in a linear direction. Energy enters the ecosystem through producers, such as plants, which convert sunlight into chemical energy through photosynthesis. This energy is then transferred to consumers, such as herbivores, which eat the plants, and then to higher-level consumers, such as carnivores, which eat the herbivores. At each trophic level, energy is lost as heat and used for metabolic processes, so it does not cycle back to the beginning. Therefore, the statement "Energy cycles through an ecosystem" is false.

Explanation

In an ecosystem, energy does not cycle but flows in a linear direction. Energy enters the ecosystem through producers, such as plants, which convert sunlight into chemical energy through photosynthesis. This energy is then transferred to consumers, such as herbivores, which eat the plants, and then to higher-level consumers, such as carnivores, which eat the herbivores. At each trophic level, energy is lost as heat and used for metabolic processes, so it does not cycle back to the beginning. Therefore, the statement "Energy cycles through an ecosystem" is false.

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