Which of these organisms are in a trophic level that receives a larger percentage of the energy captured by the producers than the percentage received at the bats' trophic level?

• Mountain lions

• Snakes

• Hawks

• Ground squirrels

Answer explanation

The closer an organism is to the first trophic level, the greater the percentage of energy received. The bats are in the third trophic level. So, organisms in the first or second trophic will receive a larger percentage of the energy than organisms in the third or fourth trophic levels.

Tags

NGSS.MS-LS2-3

A student is asked to draw a food web in which the same organism is a primary consumer as well as a secondary consumer. How should the organism be represented in the food web?

• The organism must have an arrow pointing away from it to a tertiary consumer and another arrow pointing from it to a decomposer.

• The organism must have an arrow pointing from it to a secondary consumer and another arrow pointing from it to a top predator.

• The organism must have an arrow pointing to it from a producer and another arrow pointing to it from a primary consumer.

• The organism must have an arrow pointing from it to a primary consumer and another arrow pointing away from it to a decomposer.

Answer explanation

In a food web, the arrows point to the organism doing the consuming (like the arrow is pointing to the mouth doing the eating). In order for an organism to be a primary consumer, it must have an arrow pointing to it from a producer. Also, in order for the organism to be a secondary consumer, the organism must have an arrow pointing to it from a primary consumer.

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-3

A terrestrial food web is shown. Which of the following only lists organisms that are secondary consumers in this food web?

• Mice, rabbits, herbivorous insects, and squirrels

• Predaceous insects, toads, spiders, and foxes

• Spiders, foxes, owls, hawks and snakes

• Insectivorous birds, seed-eating birds, owls, and hawks

Tags

NGSS.MS-LS2-3

A student sets up a compost bin outdoors. Inside the bin, microorganisms convert the student's vegetable and paper scraps into rich fertilizer. Which of the following best describes the role that these microorganisms play in natural habitats?

• The microorganisms help balance the numbers of producers and consumers.

• The microorganisms help keep nutrients cycling through the ecosystem.

• The microorganisms turn solar energy into sugars.

• The microorganisms function as autotrophs.

Tags

NGSS.MS-LS2-3

A small town in the piney woods of East Texas has a soccer field composed of native grasses.

The soccer field is mowed once a week.

What effect does continual mowing have on the ecology of the field?

• Mowing increases the likelihood of non-native species displacing native species.

• Mowing increases the number of species found on the field.

• Mowing causes different types of communities to form across the field.

• Mowing maintains a low species diversity by inhibiting further succession.

Tags

NGSS.MS-LS2-4

Four common relationships between organisms are listed in the box.

Which statements best describe these relationships?

• Mutualism: 1 and 4

  Commensalism: 2

  Parasitism: 3

• Mutualism: 1 and 2

  Commensalism: 3 and 4

• Mutualism: 2 and 4

  Commensalism: 1

  Predation: 3

• Mutualism: 1, 2 and 4

  Parasitism: 3

Tags

NGSS.MS-LS2-2

Some relationships between different organisms are shown in the box.

Which table correctly identifies each type of interaction described?

• 
• 
• 
• 

Tags

NGSS.MS-LS2-2

On March 24, 1989, an oil tanker ran aground on Bligh Reef in Prince William Sound, Alaska, and spilled millions of liters of crude oil. The graph shows pink salmon populations in Prince William Sound from 1970 to 1999.

What do these data suggest about the effect the oil spill had on pink salmon?

• Pink salmon were nearly eliminated after the oil spill.

• Pink salmon populations seemed to be minimally affected.

• Pink salmon populations steadily declined in the 10 years following the spill.

• Pink salmon populations declined and never fully recovered.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

In the mid-1980s an aggressive strain of algae known as Caulerpa was accidentally introduced into the Mediterranean Sea when a seaside aquarium cleaned out its tanks. The algae contains a toxin that prevents native herbivores from consuming it. Caulerpa quickly spread over the sea floor, crowding out many species including sponges, corals, sea fans, and lobsters.

Which statement explains the most likely impact Caulerpa has had on the biodiversity in the Mediterranean Sea?

• The presence of Caulerpa within an ecosystem is an indicator of an ecosystem's health.

• The spread of Caulerpa improved the habitat for many species of sea grasses, and increased the biodiversity.

• Caulerpa interbred with native species with the same adaptations within the ecosystem.

• Caulerpa became dominant within the ecosystem and reduced the biodiversity.

Tags

NGSS.MS-LS2-4

Which statement is an example of how carbon moves through a food chain as part of the carbon cycle?

• Producers release carbon dioxide, and consumers take it in.

• Producers take in carbon dioxide, and consumers release it.

• Producers take in carbon from the soil, and they release it when they decompose.

• Producers release carbon into the soil, and consumers take it in from the soil.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3