The Laws of Conservation of Mass and Energy and Interdependence: A Rabbit's Story

Question

In the natural world, every living organism interacts with its environment in a way that follows the Laws of Conservation of Mass and Energy. One example of a consumer that plays a crucial role in these cycles is the rabbit. Rabbits are herbivores, which means they primarily eat plants.

When a rabbit eats a plant, it consumes leaves, stems, and roots. These plant parts are rich in a sugar called glucose, which is produced through a process known as photosynthesis. During photosynthesis, plants use sunlight, carbon dioxide from the air, and water from the soil to create glucose and oxygen. When the rabbit eats the plant, it breaks down the glucose through a process called cellular respiration, which helps the rabbit convert the stored energy in the glucose into a form it can use for its daily activities, like running, jumping, and staying warm. As rabbits consume glucose, the primary product of of photosynthesis, they also breathe in oxygen from the atmosphere, the second product of photosynthesis.

The primary product of cellular respiration, chemical energy (ATP), is released during cellular respiration and powers the rabbit’s movements and bodily functions. Additionally, as rabbits breathe out, they release carbon dioxide, the second product of cellular respiration, back into the atmosphere. This carbon dioxide is then available for plants to use again during photosynthesis, demonstrating the interdependence of living systems.

Eventually, every rabbit will die, just like all living organisms. When this happens, the rabbit's body begins to decay. Decomposers, such as bacteria and fungi, break down the organic matter in the rabbit's body. This decaying process returns nutrients to the soil, enriching it with essential elements that plants need to grow. The carbon contained in the rabbit's body is also released back into the atmosphere in the form of gasses, completing the cycle.

The rabbit's life cycle illustrates the Laws of Conservation of Mass and Energy. Matter is neither created nor destroyed; it simply changes forms. The nutrients from the rabbit’s body (matter) are reused by plants, allowing them to grow and produce glucose once again. Energy is transformed through different processes, but it is always conserved in the ecosystem.

Question 1
Using only information in the passage above, explain how the process of a rabbit eating plants and eventually decaying demonstrates the Laws of Conservation of Matter and Energy. Include specific examples from the passage above that show how matter/energy is conserved (reused/recycled).

Key words to include: photosynthesis, cellular respiration, matter, energy, sunlight, carbon dioxide, oxygen, glucose,

Sentence starters:

The process of photosynthesis shows that matter and energy is conserved because...
The process of cellular respiration shows that matter and energy is conserved because...

Using only information provided within the passage, provide two examples of ways in which matter is transferred in the carbon cycle.

Answer 1

The process of photosynthesis shows that matter and energy is conserved because plants take in carbon dioxide from the atmosphere and water from the soil, using sunlight to produce glucose and oxygen. This demonstrates that the matter (carbon dioxide and water) is transformed into new forms (glucose and oxygen) but is not created or destroyed; it simply changes form as the plant uses energy from sunlight.

The process of cellular respiration shows that matter and energy is conserved because when a rabbit consumes glucose from plants, it breaks it down to extract chemical energy (ATP) for its bodily functions. As the rabbit breathes in oxygen (the second product of photosynthesis) and converts the glucose using this oxygen, it transforms the stored energy into a usable form. Furthermore, the rabbit releases carbon dioxide back into the atmosphere as a byproduct, which will subsequently be used by plants in photosynthesis, highlighting how matter and energy cycle through living systems.

Two examples of ways in which matter is transferred in the carbon cycle from the passage are:

1. When a rabbit eats plants, it consumes glucose, which contains carbon that originally came from carbon dioxide in the atmosphere, demonstrating the transfer of matter from the atmosphere to the rabbit through the process of feeding.

2. When the rabbit eventually decays after death, decomposers break down its body, returning nutrients and carbon back to the soil and the atmosphere in the form of gases, which can be taken up again by plants during photosynthesis, demonstrating the recycling of carbon matter within the ecosystem.