chapter 13 assessment

An acorn is eaten by a squirrel, which is eaten by an owl. What model best describes this simple relationship, and how does it show energy flow?

A food web models this relationship and it shows how energy flows with its arrows pointing at who gets the energy.

How might a drought affect a grassland food web? Which trophic level would the drought affect the most? Explain your answer.

A grassland food web could be affected by a drought because with no water grass, the producer, can not grow. It primarily affects primary consumers because they would not have food.

In which direction does energy flow through this energy pyramid?

B. 1,2,3,4

Which of the following groups is most important for bringing energy into an ecosystem?

B. Producers

A scientist wants to measure the size of a cactus population in a desert valley. What method should she use?

B. Quadrat sampling

Several different plant species grew in an empty lot. The city council decided to turn the lot into a park, so they had the ground torn up and planted with grass to create a playing field. The ecological factor that was most likely affected by the change was the lot's

C. Biodiversity

In the carbon cycle, through what process does carbon move from an abiotic resource into organic matter?

D. Photosynthesis

This food web shows the relationships between organisms in an ecosystem. Which type of organism not shown in this food web is important to the stability of the ecosystem?

D. decomposers

How does an energy pyramid show the flow of energy in an ecosystem?

Energy pyramids show the flow of energy in an ecosystem by showing each trophic level and how much energy is lost and transferred as it goes up the pyramid.

Use the information you learned about carbon-based molecules to explain a human's need to participate in the biogeochemical cycles.

Human participate in the biogeochemical cycle, by breathing out carbon dioxide and oxygen and it is reused in the cycle.

Humans have changed many ecosystems on Earth. Compare different types of consumers, and predict which types would be more likely to adapt to these changes and which would not. Explain your answers.

Humans have changed ecosystems and animals that would not survive can be tigers and animals that can are rabbits. The reason for this because humans will favor rabbits and they are smaller and can adapt easier compared to a tiger. Tiger would kill us and they would not be able to adapt.

What would happen to a forest ecosystem if a fire killed most of its producers?

If a fire killed the producers in an ecosystem the food chain and web would fall apart and its consumers will die.

In a pyramid of numbers, the highest organism has the smallest number of individuals in a community. What might happen if this organism increased its numbers significantly? Explain the effect this increase would have on the other members of the community.

If the organism increased its numbers then there would not be enough consumers and energy for all of them to live off of. The other members would have a decrease in numbers because the organisms need to eat causing less of the other members.

Describe one similarity and one difference between photosynthesis and chemosynthesis.

One similarity of chemosynthesis and photosynthesis is they both are used to produce energy. One difference is chemosynthesis is chemical energy and Photosynthesis's energy comes from sunlight.

If 90 percent of the energy is lost as heat between trophic levels, approximately how much energy is available to the secondary consumers in this energy pyramid? Show your calculations.

The amount of energy available to the secondary consumer is 100 kcal. 10000 x. 1=1000 1000 X. 1=100

What are the major differences between observation, experimentation, and modeling?

The differences between observation, experimentation, and modeling, observation is watching something over time, expiramentation are preformed in labs or in fields and they are controlled, and modeling is using models to describe and model nature.

A biomass pyramid and a pyramid of numbers are two ways of modeling the flow of matter in an ecosystem. What is the main difference between the two?

The main difference between a pyramid of numbers and a biomass pyramid is that a biomass pyramid Provides a picture of the mass of producers needed to support primary consumers, and so on.

What role do decomposers play in the nitrogen cycle?

The role de composers play in the nitrogen cycle is they are in the process of ammonification to make ammonium.

Scientists used to say that all living things depend on the sun. Explain why this statement is no longer valid.

The statement "all living things depend on the sun" is no longer valid because deep underwater sea vents were found at the bottom of the ocean that use chemosynthesis to make energy.

What is a keystone species and how might the removal of it affect the stability of and biodiversity within its ecosystem?

keystone species are species that have large affect on the environment . It affects the stability and biodiversity because they change the food web and environment in ecosystem.

Use the energy pyramid to describe the flow of energy within an ecosystem. Identify which tier represents producers, primary consumers, and so on.

the energy pyramid shows how much energy the producers start with and how much is lost each trophic level it goes up. The orange is the producer, the pink is the primary consumer, the purple is the secondary consumer and the green is the tertiary consumer.

Give an example of one biogeochemical cycle and explain how it is important to living things.

the nitrogen cycle is important to the environment because it cycles breathable nitrogen through the environment. It mostly occurs underground so plants can use it to make amino acids.