8.11A Competition/Dependency

An earthworm farmer wanted to grow three species of earthworms, but earthworms can be very picky about the temperature, moisture, and pH balance of their soil. This graph shows the range of soil conditions preferred by three species of earthworms in an earthworm soil bed.

Which of these conditions would cause the most competition for the resources among the three species of earthworms?

• Very warm soil, ph of 6, and dry.

• Very cold soil, pH of 7, and high moisture.

• Moderate temperature, pH of 6.5, and moderate moisture.

• Moderate temperature, pH of 7.0, and high moisture.

Bromeliads are small plants that grow attached to the sides of large trees high above the ground in warm, damp and densely crowded tropical rainforests. Bromeliads do this because they are in competition with other plants for -

• soil.
• heat.
• light.
• water.

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NGSS.MS-LS2-1

Which two organisms in this food web are COMPETING for food with each other?

• Cougar and Deer
• Rabbit and Snake
• Insects and Grass
• Shrew and Mouse

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NGSS.MS-LS2-1

Three different bird species live in the same tree, but competition rarely occurs.  How can this be explained?

• occupy different niches
• eat the same food
• have a limited supply of food
• live in the same part of the tree

Temperature, light, air, water, and soil are all  _____  parts of the environment

• alive
• biotic 
• abiotic
• living

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NGSS.MS-LS2-3

Which organisms in the food web shown above compete for the same food source in this environment?

• Grasshoppers and snakes
• Hawks and frogs
• Frogs and snakes
• Decomposers and grasses

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NGSS.MS-LS2-1

What would best explain the decrease in primary producers?

• an increase in solar energy
• a decrease in O2 levels in the H2O
• a decrease in the population of tertiary consumers
• an increase in the population of primary consumers

What would likely be the result if a pesticide is used to reduce the # of harvester ants?

• an increase in snakes & a decrease in hawks
• a decrease in snakes & an increase in hawks
• a decrease in mesquite bushes & an icnrease in horned lizards
• an increase in mesquite bushes & a decrease in horned lizards

In Southern California, the intentional reduction of the coyote population has led to a decrease in the types of song birds in that area.  Which is a likely explanation why song bird populations have decreased?

• Coyotes feed on animals that prey on song birds.
• Coyotes protect nests built by bird songs.
• Song birds are killed by diseases carried by coyotes.
• Song birds feed on animal matter killed by coyotes.

A farmer plows a field of grass to plant crops.  Which population of animals will MOST likely be impacted the greatest from the habitat change?

• deer that feed on field plants
• birds that nest in forest trees
• moles that burrow in shallow soil
• insects whose larva feed on dead animals