7th Benchmark Review

1a. What is rotation? Earth spinning on its axis (takes 24 hrs for a complete rotation).

1b. What is revolution? Earth’s orbit around the sun (it takes 365 ¼ days to complete one revolution)

1c. What is the magnetic field and why is it important? How is it made? A protective layer of charged particles surrounding the earth. It is important because it protects us from harmful particles from the sun (CME’s- coronal mass ejections). It is made by the liquid iron found in Earth’s outer core.

1d. How does the density (mass) of a planet affect the weight of a traveler on it? The larger (more dense) the planet, the greater its gravitational pull. The greater the gravitational pull, the higher your weight (a measure of gravity’s pull on you) is. You will weigh more on larger (more dense) planets because of increased gravitational pull.

1e. What causes day and night? Day occurs when you are facing the sun, then the earth rotates on its axis and you are facing away from the sun, this is called night. Earth’s rotation causes day and night to occur.

1f. What causes the seasons? Earth’s tilted axis causes earth to be tilted towards the sun or away from the sun as it orbits the sun. When the northern hemisphere is tilted towards the sun, it is getting direct light and longer hours of day light, this increases the temperature and you get summer. When the northern hemisphere is tilted away from the sun, there is indirect light, fewer hours of sunlight and colder temperatures, this is winter.

1g. Are seasons the same for the northern and southern hemisphere? Seasons are opposite for the northern and southern hemispheres. (for example: our spring is Australia’s fall) See picture above.

2a. Compare and contrast rocks and minerals Minerals must be 1. Solid, 2. Inorganic (no living/once living pieces like fossils or shells), 3. Have a specific chemical recipe, 4. Have a crystal (repeating atom pattern) structure, 5. Must be naturally made. Rocks can have organic material, don’t have a crystal structure, don’t have a specific recipe.

2b. What are the stages of the rock cycle and how does it change form?

2c. How do layers of rocks tell us about their age? Older rocks are generally found at the bottom of an undisturbed layer of rocks. Rocks found at the same level are the same age. Sea life fossils can be lifted high into the mountains when plates shift around and erosion exposes them.

2d. What four pieces of evidence do we have to support the theory of continental drift? These four clues tell us the continents were once connected and used to be in different places around the globe. Matching animal fossils on different continents Matching plant fossils on different continents Climate clues (glacier scrapes in Africa and tropical plant fossils in Antarctica) Matching rock formations (mountain ranges) on different continents

2e. What is physical and chemical weathering and what are some examples? Chemical weathering: breaking down rocks through chemical changes (dissolving the chemical bonds) examples: acid rain, water (dissolving), oxygen (rust), carbon dioxide (dissolving), living organisms (dissolving) Physical weathering: Rocks are physically broken into smaller pieces. Examples: freezing and thawing, plant growth, animals burrowing, friction and impact, temperature change.

2f. What is eroding and what are some examples? Erosion is the removal of rocks. Rocks can be removed by the following processes: wind, gravity, water (streams/rivers/oceans), or glacial movement (ice)

2g. Where do volcanoes and earthquakes commonly occur? Most commonly occur along plate boundaries (edges) because that’s where the plates shift and move against each other. The largest area of volcano and earthquakes are the Ring of Fire around the Pacific Ocean.

3a. What are the five characteristics of all living things? Made of cells, grow and develop, respond to environment, reproduce, and use energy

3b. What are the first five levels of organization? Cells, tissue, organ, organ system, organism

3c. Compare and contrast plant, animal and bacterial cells. Plant and animal cells have a nucleus (eukaryotic), bacteria cells are much smaller and have no nucleus (prokaryotic)

3d. Compare and contrast prokaryotic and eukaryotic cells Prokaryotic – no nucleus, Eukaryotic –has a nucleus and other membrane bound organelles

3e. What are some examples of inherited traits? Freckles, rolling tongue, skin color, eye color

3f. Be able to do a Punnett square Heterozygous (Bb), Homozygous (BB or bb). Genotype are the genes for a trait (BB), Phenotype is the physical appearance of a trait (brown eyes)

3g. How is an organism able to start growing at only one cell big? Cell will undergo mitosis to make more cells.

3h. Compare and contrast sexual and asexual reproduction.