1. 7th Grade science review
Second semester

2. 7th Grade science review: Ecosystems
How does the availability of resources in ecosystems affect populations of organisms?
Wildlife populations depend on their environment or habitat to receive the basic needs for survival. An ecosystem or habitat provides populations of wildlife with food, water, shelter and space. If all four of these basic needs are not available in a suitable arrangement, populations of wildlife can not exist.
All populations of living things are interrelated. When one population of animals, plants, or insects increase or decrease, other populations of living things are also affected. For example, when shrubs and brushy areas are removed from an ecosystem, the rabbit population will likely go down. The reduced rabbit population will lower predator populations that use rabbits as a food source.

3. 7th Grade science review: Ecosystems
What is symbiosis?
The close association between two or more organisms of different species, often but not necessarily benefiting each member. 
What are the three types of symbiosis?
Mutualism: Both species benefit/the relationship is mutually beneficial
Commensalism: One species benefits, the other is unharmed or unaffected
Parasitism: One species benefits, the other is harmed or killed

4. 7th Grade science review: Ecosystems
Mutualism
Commensalism
Parasitism

5. 7th Grade science review: Ecosystems
What might cause a population to stop growing?
For a population to be healthy, factors such as food, nutrients, water and space, must be available.
Limiting factors are resources or other factors in the environment that can lower the population growth rate. Limiting factors include a low food supply and lack of space. Limiting factors can lower birth rates, increase death rates, or lead to emigration. 

6. 7th Grade science review: biodiversity
What is biodiversity?
Biodiversity refers to all the different kinds of living organisms within a given area.
How does biodiversity impact human health?
Economic Benefits: a variety of organisms provide humans with many different products, including timber, fibers, adhesives, dyes, and rubber.
Medical Benefits: more than half of the most important prescription drugs come from wild plant species. Declining biodiversity can indirectly harm human health.

7. 7th Grade science review: biodiversity
Ecosystem Services of Biodiversity:
Plants and algae maintain the atmosphere. During photosynthesis, they add oxygen and remove carbon dioxide.
Plants help prevent soil erosion.
Microorganisms purify water in rivers and lakes.
Microorganisms also return nutrients to the soil.
Insects and birds pollinate flowering plants, including crop plants.
Natural predators control insect pests.

8. 7th Grade science review: earth’s resources
~ “Americans will drain as many resources as 35 natives of India and consume 53 times more goods and services than someone from China.”
Why do populations in different countries around the world consume resources at different rates?
Money – citizens can afford to purchase goods and services
Availability – goods and services are readily available
Technology – technological advances require more resources
Culture – cultural values help dictate priorities

9. 7th Grade science review: earth’s resources
What does ‘non-renewable’ mean?
any natural resource from the Earth that exists in limited supply and cannot be replaced if it is used up.
Renewable
Nonrenewable
Solar Energy
Oil
Wind Energy
Natural Gas
Geothermic Energy
Coal
Hydropower
Uranium (Minerals)

10. 7th Grade science review: earth’s resources
What does ‘sustainable’ mean?
a method of harvesting or using a resource so that the resource is not depleted or permanently damaged.
How can you help conserve our natural resources?
Use less plastic
Walk to school or carpool
Turn off lights/electricity when not in use
Recycle/Reuse/Repurpose used items instead of throwing them away

11. 7th Grade science review: earth History

12. 7th Grade science review: earth History

13. 7th Grade science review: earth History

14. 7th Grade science review: earth History

15. 7th Grade science review: earth History
Basalt
Igneous Extrusive
Formed by lava on Earth’s surface
Cools rapidly
Few or no crystals
Gas bubbles
Granite
Igneous Intrusive
Formed by magma inside the Earth’s crust
Cools slowly
Large crystals

16. 7th Grade science review: earth History
Law of Superposition:
a law in geology: where there has been no subsequent disturbance sedimentary strata were deposited in ascending order with younger beds successively overlying older beds (oldest layers are on the bottom)

17. 7th Grade science review: earth History
Fossils:
the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
typically found in sedimentary rock
provide evidence of past life forms, environments, and climates
useful in determining the relative age of a rock layer

18. 7th Grade science review: Dynamic earth
Layers of the Earth
review Inside Earth packet
actives/dynamicearth/

19. 7th Grade science review: Dynamic earth

20. 7th Grade science review: Dynamic earth
Convection currents in the mantle drive plate tectonics.

21. 7th Grade science review: Dynamic earth
compression tension shearing

22. 7th Grade science review: Dynamic earth
Subduction: convergent plate boundaries (subduction zones) are where crustal material is recycled. Denser oceanic crust is thrust under less dense continental crust.
Sea-floor Spreading: the formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges (divergent plate boundaries) and its subsequent outward movement on either side.
Earthquakes: when two blocks of the earth suddenly slip past one another (transform plate boundaries.) The surface where they slip is called the fault or fault plane.
Mountains, volcanoes, ocean ridges, and trenches usually form at the boundaries of tectonic plates.

23. 7th Grade science review: Dynamic earth
~ Alfred Wegener proposed the theory of continental drift – the idea that Earth’s continents move.
Wegener noticed how the coastlines of eastern South America and western Africa seemed to fit together, rather like jigsaw pieces
He noticed that fossils of the same species could be found in Brazil and western Africa.
He researched geological data and found evidence of similar rock formations on the continents of South America and Africa.
He called his ‘supercontinent’ Pangaea.

24. 7th Grade science review: Dynamic earth
Weathering: the process by which rocks are broken down by wind, water or ice.
Erosion: the action of surface processes (such as water flow or wind) that remove soil, rock, or dissolved material from one location on the Earth's crust, then transport it away to another location.
Deposition: the process in which sediments, soil and rocks are added to a landform or land mass. Wind, ice, and water, as well as sediment flowing via gravity, transport previously eroded sediment which is then deposited, building up layers of sediment.

25. 7th Grade science review: Natural Disasters
How do scientists predict catastrophic meteorological and geologic events?
Doppler Radar: a radar tracking system using the Doppler effect to determine the location and velocity of a storm, clouds, precipitation, etc.
Seismograph: an instrument that detects and records vibrations and movements in the Earth, especially during an earthquake.
Computer Models: the applied science of creating computerized representations of portions of the Earth's crust based on geophysical and geological observations made on and below the Earth surface.

26. 7th Grade science review: Natural Disasters
Be Prepared
Have a plan
Have supplies
Know who to call

27. 7th Grade science review: Engineering
The Design Process:
Define the Problem
Generate Concepts
Develop a Solution
Construct and Test a Prototype
Evaluate the Solution
Present the Solution

28. 7th Grade science review: Engineering
Passive Solar Energy:
Using sunlight without machinery/mechanical devices.
Solar energy is converted into thermal (heat) energy
Available everywhere, free, and renewable.

29. 7th Grade science review: Engineering
Active Solar Energy:
Converting solar energy into usable electricity and heat using mechanical equipment like pumps and fans. (ex. Solar panels)
Can be used for homes and heating swimming pools.

30. 7th Grade science review: Engineering
Scale Drawings
Plans are usually "scale drawings", meaning that the plans are drawn at a specific ratio relative to the actual size of the place or object.
Various scales may be used for different drawings in a set. For example, a floor plan may be drawn at 1/4"=1'-0“ whereas a detailed view may be drawn at 1/2"=1'-0".