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An introduction to the living and non-living parts of our environment and how they interact.
Imagine you are a tiny frog in a pond. To stay alive, you need more than just your frog friends—you need the water, the sunlight, and even the air. How do all these different things work together to keep you healthy?
Every environment is made of two main ingredients. First, we have biotic factors. These are the living parts, like plants, animals, and even tiny bacteria. Think of 'bio' as meaning 'life.' Second, we have abiotic factors. These are the non-living parts that have never been alive, such as sunlight, temperature, soil, and water ().
Even though abiotic factors aren't alive, they are the 'stage' where life happens. Without the sun's energy or the oxygen () in the air, the biotic factors couldn't exist. Scientists study how these two groups dance together to create a balanced world.
Quick Check
If you are looking at a desert, is the sand a biotic or abiotic factor?
Answer
The sand is an abiotic factor because it is a non-living part of the environment.
Living things are not independent; they are dependent on their surroundings. This means they rely on abiotic factors to stay alive. For example, plants need sunlight to perform photosynthesis and create food. Animals need water to drink and oxygen to breathe.
Sometimes, biotic factors also depend on other biotic factors. A bee depends on a flower for nectar, and the flower depends on the bee to spread its pollen. This web of 'who needs what' is what keeps nature running smoothly. If you change one abiotic factor—like making the temperature hotter—it can change the lives of every living thing in that area.
Let's look at a simple pond to see how things interact: 1. Sunlight (Abiotic) shines on the water. 2. Algae (Biotic) uses that light to grow. 3. Small fish (Biotic) eat the algae to get energy. 4. The Water (Abiotic) provides a home and oxygen for the fish.
Quick Check
What might happen to the fish if the sunlight was blocked for a long time?
Answer
The algae would stop growing without sunlight, leaving the fish with no food.
When you put all the biotic and abiotic factors together in one specific area, you get an ecosystem. An ecosystem is a community of organisms interacting with their physical environment.
Ecosystems can be huge, like the entire Amazon Rainforest, or tiny, like the space under a single fallen log. The size doesn't matter as much as the interaction. In a healthy ecosystem, everything is in balance. The amount of available water () matches the number of animals drinking it, and the plants produce enough oxygen () for the creatures to breathe.
Even a dead log is a busy ecosystem! 1. Decomposers: Fungi and beetles (Biotic) break down the wood. 2. Moisture: Rainwater (Abiotic) trapped under the log keeps the soil damp. 3. Shelter: The log provides a dark, cool place (Abiotic temperature control) for salamanders to hide from the sun. 4. Nutrients: As the log rots, it adds minerals to the Soil (Abiotic), helping new seeds grow.
Which of the following is an abiotic factor?
What defines an 'ecosystem'?
Plants are considered abiotic because they do not move around like animals.
Review Tomorrow
In 24 hours, try to list three biotic and three abiotic factors you can see from your window.
Practice Activity
Find a 'micro-ecosystem' near your home, like a patch of grass or a puddle. Write down two ways the living things there are using the non-living things.