Ecosystems and Populations
What do you call all the living and non-living things in an environment?
What is an ecosystem?
What is the niche?
What consists of about 78% nitrogen gas and 21% oxygen gas.
The atmosphere
What percentage of the air you breathe is nitrogen gas?
~78%
What is the word equation for photosynthesis?
Carbon dioxide + water + energy 🡪 glucose + oxygen
What is the name for a group of the same species living in a particular area?
What is a population?
What would happen to the food chain if all the producers were removed?
What is the collapse of the food chain due to lack of energy sources?
What is the biosphere?
The biosphere is the part of Earth where life exists, including land, water, and the atmosphere. It’s where all living things are found.
How does the biosphere depend on the hydrosphere?
Living organisms rely on water for survival?
Why is sunlight important for photosynthesis?
Sunlight provides the energy plants need to make food through photosynthesis. It helps plants turn carbon dioxide and water into glucose (food) and oxygen.
Explain the difference between extinct and endangered.
A species is considered extinct when there are no living members left anywhere on Earth.
A species is considered endangered when it is at risk of extinction in the near future.
What is the difference between a food chain and a food web?
A food chain shows a single path of energy flow, while a food web shows interconnected energy paths in an ecosystem.
Name 5 places where you can find water in the hydrosphere
Lakes, rivers, oceans, plants, animals
Why is the nitrogen cycle critical for agriculture?
The nitrogen cycle is important for farming because plants need nitrogen to grow. Bacteria turn nitrogen from the air into a form plants can use, and dead plants and animals return nitrogen to the soil. This helps keep the soil healthy and crops growing well.
How does photosynthesis help to support life on Earth?
Photosynthesis creates oxygen and food for plants, which animals rely on for survival. It also helps remove carbon dioxide from the air, supporting life on Earth.
If twenty male and female deer are introduced onto a bush and grass covered island where there are no natural enemies, what will most likely happen in future years?
The deer population will continue to increase until there is very little bush or grass left
Why does the introduction of an invasive species often lead to population imbalances?
Top predators are most affected because they eat lots of smaller animals, and the toxins in their food build up in their bodies over time. The toxins get more concentrated as they move up the food chain, so predators like eagles, sharks, or wolves end up with the highest levels of harmful substances.
How does the biosphere depend on the hydrosphere?
The biosphere depends on the hydrosphere for water, which is essential for all life. Water supports plant growth, provides drinking water for animals, and helps maintain ecosystems.
Explain how decomposition contributes to the carbon cycle.
Decomposition breaks down dead plants and animals, releasing carbon back into the soil and air as carbon dioxide. This helps recycle carbon, keeping it moving through the ecosystem.
What is the relationship between photosynthesis and cellular respiration?
1. Photosynthesis makes food and oxygen, while cellular respiration uses oxygen to break down food for energy.
2. They are complementary reactions.
Give 4 examples of environmental resistance and explain them.
Natural disasters, predation, competition, disease and parasitism, habitat destruction, climate, reproductive limits, etc.
Top predators are most affected by biomagnification because they are at the highest level of the food chain and consume organisms from all levels below them. Biomagnification refers to the process where the concentration of toxic substances, such as mercury, DDT, or PCBs, increases as it moves up the food chain.
How does the water cycle contribute to the distribution of water on Earth?
The water cycle moves water around Earth through processes like evaporation, condensation, and precipitation.
How does human reliance on fossil fuels alter the natural balance of the carbon cycle?
Burning fossil fuels adds extra carbon dioxide to the air, faster than plants and oceans can absorb it. This upsets the carbon cycle and contributes to climate change.
How does cellular respiration contribute to the carbon cycle?
Cellular respiration releases carbon dioxide when organisms break down food for energy. This carbon dioxide goes back into the air, completing the carbon cycle.