Science Starr

Giant salvinia is an aquatic plant that floats on water and reproduces rapidly. When these plants die, decomposition by bacteria affects oxygen levels in the water. As more plants die, less oxygen is available in the water. Students observe a pond covered by giant salvinia. Which statement is the best prediction the students can make about the immediate future of the pond?

• The depth of the water in the pond will increase.

• Fish populations in the pond will begin to decrease.

• The amount of bacteria in the pond will suddenly decrease.

• The number of different types of plants around the pond will increase.

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NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-3

NGSS.MS-LS2-4

Plants grow in many different shapes and sizes. Much of their shape depends on an internal structure that is composed of carbon-containing molecules such as cellulose and lignin. Plants that have a strong internal structure can grow larger than other plants because their structure can support their size.

Plants obtain the majority of the carbon necessary for building these structural molecules from —

• air

• microorganisms

• soil

• water

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NGSS.MS-LS1-5

NGSS.MS-LS2-3

A group of scientists studied some trees in a pine forest. In the densely forested areas, the trees were within 1 m of each other. The scientists observed that these trees had dead branches near the ground. They measured the height above the ground at which the first living branches were found on different-sized trees in the forest. Then they repeated this procedure on the same kind of trees in an open meadow. This graph summarizes the scientists’ data.

Which inference is best supported by these data?

• Pine trees in a dense forest can grow taller than pine trees in an open meadow.

• Pine trees in a dense forest compete for sunlight with the surrounding trees.

• Pine trees in a dense forest are part of a less-complex food web than pine trees in an open meadow.

• Pine trees in a dense forest have more living branches than pine trees in an open meadow.

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models growth of the bacteria over time. Which of these most likely explains why the bacterial population stopped growing?

• The bacteria competed for nutrients and died after all the nutrients were consumed.

• The bacteria did not reproduce in the system, and eventually each individual died at the end of its life cycle.

• The bacteria mutated from photosynthetic to carnivorous organisms and consumed one another until all the individuals were dead.

• The bacteria became diseased and were unable to survive in the closed system.

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NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Design a project to compare the effects of physical changes (such as temperature and pressure) on different states of matter.

• Heat and cool water, ice, and steam to observe changes in state and record temperatures at which these changes occur.

• Freeze and melt different metals to see which one has the highest melting point.

• Apply pressure to various solids to determine their hardness.

• Observe the color changes in substances when heated without measuring temperature.

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DOK Level 4: Extended Thinking

What do you call the science of studying space?

• astrology

• astronomy

• physics

• chemistry

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NGSS.MS-ESS1-1

NGSS.MS-ESS1-2

NGSS.MS-ESS1-3

What do you call the science of studying space?

• astrology

• astronomy

• physics

• chemistry

Tags

NGSS.MS-ESS1-1

NGSS.MS-ESS1-2

NGSS.MS-ESS1-3

NGSS.MS-PS2-4

What is not a property of all matter?

• Mass

• Volume

• Color

• Density

What is the boiling point of water?

• 100 degrees Celsius

• 50 degrees Celsius

• 0 degrees Celsius

• 200 degrees Celsius

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

What is the name of our galaxy?

• Andromeda

• Milky Way

• Whirlpool

• Sombrero