STAAR Ecology

Leaf-cutter ants harvest leaves and carry them to fungi that convert

plant material into a usable form for the ants to digest. The fungi

depend on the leaves for nutrients. The ants also produce an antibiotic

on their bodies that helps protect the fungi from harmful bacteria.

Which of these explains the relationship between the leaf-cutter ants

and the fungi?

• Predation, because the ants feed on the fungi

• Mutualism, because both the ants and the fungi benefit from 

  each other

• Competition, because both organisms consume the same resource

  for energy

• Commensalism, because the ants receive energy from the fungi

  and the fungi are unaffected

Tags

NGSS.MS-LS2-2

Students designed an experiment to model the carbon cycle. The

students combined water and carbon dioxide-producing disks in a

sealed flask. The flask represented Earth’s atmosphere, and the lamp

represented the sun. Which component can be added to the flask to reduce the

concentration of carbon dioxide in the model atmosphere created 

by the disks?

• Bacteria to use carbon during nitrification

• Plants to absorb carbon in the process of photosynthesis

• Snails to use carbon through cellular respiration

• Mushrooms to absorb carbon during decomposition

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

On average, how much energy is lost between each trophic level?

• 0%

• 10%

• 90%

• 100%

Tags

NGSS.MS-LS2-3

In a Central Texas grassland, the producers incorporate 12,000 kJ of

energy from the sun into their tissues. About how much energy would

be incorporated into the tissues of herbivores?

• 12,000 KJ

• 1,200 KJ

• 10,080 KJ

• 1,008 KJ

Tags

NGSS.MS-LS2-3

White clovers, Trifolium repens, are plants that are native to Europe

and Central Asia and are able to produce the poison cyanide within

their cells. Skunk cabbage, Symplocarpus foetidus, is a plant that

is native to eastern North America and can produce a chemical that

makes it have a strong, foul odor and bitter taste.

The chemicals produced by both the white clovers and skunk

cabbages are adaptations that allow them to —

• attract more pollinators

• survive a long-term drought

• protect against herbivores

• grow better in colder habitats

Tags

NGSS.MS-LS4-4

In some coral reefs, a symbiotic relationship exists between pygmy

seahorses and sea fans. The pygmy seahorse can wrap its tail around

the branches of the sea fan. This allows the pygmy seahorse to be

camouflaged within the sea fan, protecting it from predators. The

pygmy seahorse does not harm or benefit the sea fan while it grasps

the branches with its tail

• Predator/prey

• Mutualism

• Commensalism

• Parasite/host

Tags

NGSS.MS-LS2-2

After a wheat field is cleared, wild grasses and weeds begin growing.

This process is considered —

• primary succession because pioneer species appear

• primary succession because there are no large trees

• secondary succession because soil is already present

• secondary succession because the field contains inorganic matter

During an extended dry season in an area, the majority of the ground

cover dried up. Which description best explains how this would affect

the ecosystem in that area?

• The ecosystem would become less stable because the ranges of

  many organisms would expand and overlap

• The ecosystem would become more stable because there would be

  less competition among canopy plants

• The ecosystem would become less stable because less energy

  would be available to it from the decrease in producers

• The ecosystem would become more stable because organisms in

  higher trophic levels would be able to find prey more easily

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Gradual and orderly process of change in an ecosystem until a stable community is established.

• Ecological Succession

• Biodiversity

• Adaptation

• Competition

Tags

NGSS.MS-LS2-4

Which trophic level will receive the most energy from the sun?

• A

• B

• C

• D

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3