Ecosystems and Energy
Plants get the energy they need for growth chiefly from this celestial source.
The Sun
Roughly this percentage of Earth's water is found in the oceans as saltwater.
97%
Scientists collect this to support their ideas.
Evidence
Communities can protect the hydrosphere by reducing the runoff of these chemicals used on farm crops.
Fertilizers or pesticides
These are the limitations or "roadblocks" an engineer faces, such as lack of materials or time.
Constraints
These organisms, such as fungi and bacteria, break down dead plants and animals and return nutrients to the soil.
Decomposers
Most of Earth's freshwater is not found in lakes or rivers, but is actually "locked up" here.
Glaciers and ice caps
If you freeze 100 grams of water into ice, the weight of the ice will be exactly this.
100 grams
Name one way your community can protect Earth's fresh water resources.
Reduce water pollution, clean up litter from rivers, conserve water use, or recycle
A design has two possible solutions: Material A costs $5 and lasts 2 years. Material B costs $10 and lasts 5 years. Which solution is more cost-effective?
Material B (Lower cost per year: $5/year vs. $2/year)
In a food web, this type of organism must eat other living things to get energy because it cannot make its own.
Consumer
This sphere is the envelope of gases (mostly nitrogen and oxygen) that surrounds our planet.
Atmosphere
If you mix 10g of salt and 50g of water, the total mass is this.
60 grams
These are things people get from Earth that they use.
Natural resources
What does it mean to conduct a "fair test" in engineering?
Change only ONE variable while keeping everything else the same
While plants get energy from light, they get most of the actual material for body repair and growth from these two things.
Air and water
If you had 100 gallons of water to represent all the water on Earth, only about 3 gallons would be this type of water.
Freshwater
A student mixes sugar into water and notices the sugar “disappears.” Explain what really happened and what stayed the same.
The sugar dissolved, but the total mass stayed the same because the sugar is still there
Communities settle near _____ to access underground water.
aquifers
Your paper airplane keeps diving straight to the ground. You decide to add a paperclip to the tail to see if it helps. If you want to know for sure if the paperclip was the fix, should you also change the wing shape at the same time? Why or why not?
No. (You should only change one thing at a time so you know which change actually fixed it.)
This is the invisible gas in the air that plants "breathe" in to build their physical structures.
Carbon Dioxide
This sphere includes all living things on Earth.
Biosphere
A student mixes salt and water and creates a graph showing the weight before and after mixing. What should the graph show about the total weight of the mixture compared to the individual substances?
The total weight of the mixture equals the sum of the salt and water weights (equal bars on the graph)
To protect the Biosphere, many communities create these protected areas of land where building and hunting are restricted to save endangered species.
National Parks (or Wildlife Preserves)
In a rainforest, the tall trees release water vapor into the air, which then turns into clouds and falls back down as rain to water the trees. Which two of Earth’s "spheres" are working together here?
The Biosphere (trees) and the Hydrosphere (rain/vapor)