Plants STAAR

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-LS1-5

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The graph below shows the percent of seeds from two plant species that sprout when grown in water containing different amounts of salt. Which of the following best summarizes the effect of saltwater on these plant species?

• Species 1 can sprout only in freshwater, and Species 2 can sprout only in saltwater

• Both species can sprout in freshwater and saltwater, but Species 2 can sprout in a higher salt concentration than Species 1.

• Both species need salt in their water, but Species 2 needs more salt than Species 1.

• Species 1 can sprout only in water with a low salt concentration, but Species 2 is not affected by the salt concentration.

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NGSS.MS-LS1-5

NGSS.MS-LS2-1

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

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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-LS1-6

NGSS.MS-LS2-3

The strangler fig is a vine that starts out as a seed in the tree canopy of the rain forest. It drops its roots down from the canopy to the forest floor.

By sprouting in the rain-forest canopy, the strangler fig seedling is exposed to more

• sunlight

• soil

• nutrients

• consumers

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NGSS.MS-LS1-5

How does this chemical help black walnut trees compete with plants growing nearby?

• By attracting herbivores to the other plants

• By suppressing the growth of the other plants

• By increasing the photosynthesis rates in the other plants

• By limiting the amount of water available to the other plants

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NGSS.MS-LS2-1

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The Prairies Region and the Cross Timbers are located in north-central Texas. The graph below shows information about eating habits of white-tailed deer in these regions. A Cross Timbers rancher is concerned about competition between the ranch animals and the deer. Based on the graph, which ranch animals compete for the most food with white-tailed deer?

• Cattle that eat grass and feed

• Goats that eat weeds and shrubs

• Turkeys that eat seeds and fruit

• Hogs that eat fruit, seeds, and feed

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NGSS.MS-LS2-1

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Farmers spray pesticides on plants to protect plants from being eaten by insects. Some individual insects have a genetic mutation that makes them resistant to the pesticides. Which best describes how only a few resistant individuals resulted in the pesticide becoming ineffective?

• the resistant insects change the toxin on the plants, making it safe for others

• the resistant insects grow larger and eat less of the plants

• the resistant insects eat the contaminated surface and leave the rest for others

• the resistant insects are able to survive to reproduce and create a population that is also resistant

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NGSS.MS-LS4-4

Which organism has the MOST energy?

• eagle/bird

• snake

• rabbit

• grass/plants

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NGSS.MS-LS1-6

NGSS.MS-LS2-3

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

• air

• microorganisms

• soil

• water

Tags

NGSS.MS-LS1-6