Food Chain Gizmo Answer Key

Posted on

Food Chain Gizmo refers to a biology assignment from a very popular and known biology website. For those who are looking for Gizmo Exploration: Food Chain answer key, you will be able to find everything below. Take a note that the correct answers are in bold. Aside from the answer key, these followings will also include the questions so that you will not get confused.

Prior Knowledge Questions:

  1. Producers are organisms that do not need eat other organisms to obtain energy.
    A. Which organism is a producer in this food chain? grass
    B. Where does the producer get its energy? The sun
  2. Consumers must eat other organisms for energy. Which organisms are consumers in this food chain?
    Hawks, snakes and rabbits.

Gizmo Warm-up

  1. What are the current populations of each organism?

Hawks: 42                          Snakes: 278                        Rabbits: 2566                    Grass: 27300

  1. Select the BAR CHART tab, and click Play ( ). What do you notice about each population as time goes by?

The population of rabbits and grass increases.

If populations don’t change very much over time, the ecosystem is in equilibrium.

  1. Notice the populations decrease as you go from the bottom of the food chain to the top. Why do you think this is so?

There are more producers than consumers so it balances out

Activity A:

Question: Predators are animals that hunt other animals, called prey. How do predator and prey populations affect one another?

  1. Observe: Run the Gizmo with several different starting conditions. You can use the +or –buttons to add or remove organisms, or you can choose Diseased from the dropdown lists.
  2. Form hypothesis: How do you think predator and prey populations affect one another?

If the predators do not kill their prey then the prey become overpopulated and become a problem

  1. Predict: Based on your hypothesis, predict how changing the rabbit population will affect the other organisms at first. Write “Increase” or “Decrease” next to each “Prediction” in the table.
Change Grass Snakes Hawks
Doubling rabbit population Prediction: decrease

Result: decrease

Prediction: increase

Result: increase

Prediction: increase

Result: increase

Halving rabbit population Prediction: increase

Result: increase

Prediction: decrease

Result: decrease

Prediction: decrease

Result: decrease

  1. Test: Add rabbits until the population is about twice as large as it was (200% of balance). Click Play, and then Pause ( ) after approximately ONE month. Next to each “Result” line in the table, write “Increase” or “Decrease.” Click Reset and then halve the rabbit population (50% of balance). Record the results for this  experiment in the table as well.

A. How did doubling the rabbit population affect the grass, snakes, and hawks at first?
The grass decreased, and the snakes and hawks increased.
B. How did halving the rabbit population affect the grass, snakes, and hawks at first?
It caused the grass to increase and the snakes and hawks to decrease.

  1. Predict: Predict how changing the snake and hawk populations will affect the other organisms within the first month. In the tables below, write your predictions.
Change Grass Rabbits Hawks
Doubling snake population Prediction: increase

Result: increase

Prediction: decrease

Result: decrease

Prediction: increase

Result: increase

Halving snake population Prediction: decrease

Result: decrease

Prediction: increase

Result: increase

Prediction: decrease

Result: decrease

Change Grass Rabbits Hawks
Doubling snake population Prediction: decrease

Result: decrease

Prediction: increase

Result: increase

Prediction: decrease

Result: decrease

Halving snake population Prediction: increase

Result: increase

Prediction: decrease

Result: decrease

Prediction: increase

Result: increase

  1. Test: Click Reset. Try each experiment with the Gizmo. Record each result after one month.

A. How did increasing the snakes affect the grass? When the snakes increased the grass also increased.
Explain why: Increasing the snake population caused a decrease in rabbit population which allowed the grass to increase.
B. How did increasing the hawks affect the rabbits? Increasing the hawks caused the rabbit to increase.
Explain why: An increase in hawks caused a decrease in the snake population which allowed the rabbit population to increase.

  1. Draw conclusions: In general, what effect did removing prey have on predators?

It will cause a decrease in predators because they will not have prey to consume.
What effect did removing predators have on prey?
It allows the prey to increase because there are no predators to consume them.

If you want to know the answer key of the Activity B, you are suggested go to  link here.

Leave a Reply

Your email address will not be published.