ABC Science

Whitetip reef sharks spend most of the day lying on the ocean floor. While remaining still, these sharks pump water across their gills.

The movement of water across their gills is necessary for —

• staying cool

• accessing food

• obtaining oxygen

• avoiding predators

A farmer digs a small pond in a pasture. The farmer adds young individuals from two species of algae-eating fish to the pond and plants some reeds around the edges of the pond. The farmer wants the pond to be a sustainable ecosystem. Which of the following would be most helpful in increasing the pond ecosystem’s sustainability?

• Decreasing the number of plant species around the edges of the pond

• Introducing older fish of the same species into the population of algae-eating fish

• Having a greater diversity of living organisms in the pond

• Adding gravel between the water and where the reeds are planted

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An ecosystem that is not sustainable can break down when a natural disaster occurs. This can lead to organisms in the ecosystem either leaving the area or dying off. Increased biodiversity results in a more sustainable ecosystem because —

• a greater number of plant species means that there is less barren land

• a greater variety of species present allows more organisms to adapt after changes occur

• the transition area between two ecosystems is narrower

• there are fewer species to be affected by environmental stresses

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NGSS.MS-LS2-4

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A drought has hit this grassland biome. How will this effect the rabbit population?

• The rabbits will increase in number.

• The rabbit population will stay the same.

• The rabbit population will decrease.

• The rabbit population will become extinct immediately.

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Fish in a lake have to compete for space. Different fish have different optimal temperature ranges. The graph below shows the temperature ranges of four fish species.

At which temperature range will there be the most competition for space among these fish species?

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The Couch's spadefoot lives in Texas and has characteristics listed in the table.

The Couch's spadefoot is adapted to a certain type of environment. Which of these resources is most likely scarce in this environment?

• soil

• sunlight

• water

• oxygen

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An ecosystem that is not sustainable can break down when a natural disaster occurs. This can lead to organisms in the ecosystem either leaving the area or dying off.

Increased biodiversity results in a more sustainable ecosystem because --

• a greater number of plant species means that there is less barren land

• a greater variety of species present allows more organisms to adapt after changes occur

• the transition area between two ecosystem is narrower

• there are fewer species to be affected by the environmental stresses

Tags

NGSS.MS-LS2-4

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Tropical rain forests have the greatest biodiversity of any type of land ecosystem. How does biodiversity contribute to the sustainability of an ecosystem?

• The presence of more species with different adaptations makes it more likely that some organisms will survive an ecological disaster.

• Greater genetic variation within species makes it more likely that some individuals will survive a disease outbreak.

• The presence of a variety of herbivore species that can feed on a large number of different producer species helps ensure abundant prey for predators in the ecosystem.

• All of the above

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Plants that live on the floors of densely populated forests must compete for sunlight. Which type of leaves are most likely found on plants that are best suited to living on the floor of a dense forest?

• Leaves that are needle-shaped

• Leaves that are smallest

• Leaves that store the greatest amount of water

• Leaves with the greatest amount of surface area

Tags

NGSS.MS-LS2-1

A farmer digs a small pond in a pasture. The farmer adds young individuals from two species of algae-eating fish to the pond and plants some reeds around the edges of the pond. The farmer wants the pond to be a sustainable ecosystem. Which of the following would be most helpful in increasing the pond ecosystem's sustainability?

• Decreasing the number of plant species around the edges of the pond

• Introducing older fish of the same species into the population of algae-eating fish

• Having a greater diversity of living organisms in the pond

• Adding gravel between the water and where the reeds are planted

Tags

NGSS.MS-LS2-1

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