Basketball

8th Grade ScienceMr. Olsen

Rose Grass Hawk SnakeMushroom Antelope Cougar FrogMaple Tree Bacteria Aspen Tree Worms

Which organisms are consumers?

1. Suppose rural farmers in your community are having problems with wolves killing their sheep. The wolves normally eat rabbits, and rabbits eat wild grasses and shrubs. When there aren’t enough rabbits, wolves move closer to ranches and take sheep. Which of these is the best hypothesis for finding a solution to this problem? Explain your reasoning.

a. if the wolf population were increased, then the number of rabbits would decreaseb. if there were more sheep, then the wolf kills would increasec. if there were fewer rabbits, then there would be fewer wolves aroundd. if there were more rabbit food, then there would be more rabbits

Elodea is an underwater plant. AGoodly sample of Elodea is placedunder a graduated glass beakerunder a bright light. The glassbeaker is balanced even on 3identical rocks so it is off the floor ofthe tank. See the diagram.

1. What would you expect to see after 20 minutes?

a. a gas will collect in the beakerb. the Elodea will shrivelc. bubbles will come out of the beakerd. the Elodea will turn a darker green

       

Rose Grass Hawk SnakeMushroom Antelope Cougar FrogMaple Tree Bacteria Aspen Tree Worms

• Which organisms are producers?

1) Which substances are the products of photosynthesis?

a. carbon dioxide and oxygenb. carbon dioxide and waterc. glucose (sugar) and oxygend. glucose (sugar) and water

1. Which level of the food pyramid contains the most energy?a. Ab. Bc. Cd. D

2. In what main form is energy lost

as you move up the pyramid?a. light energyb. chemical energyc. heat energyd. nuclear energy

Many scientists believe Earth’s early atmosphere had no oxygen.

Humans need oxygen to survive. According to some theories plants

had to photosynthesize before humans could live on Earth. What

evidence backs up this statement?

a.     Humans cannot survive without water.

b.     Doctors tell us both plants and humans need sunlight.

c.     Plants use carbon dioxide and water to photosynthesis.

d.     Plants give off oxygen during photosynthesis.

 

Elodea is an underwater plant. Agoodly sample of Elodea is placedunder a graduated glass beakerunder a bright light. The glassbeaker is balanced even on 3identical rocks so it is off the floorof the tank. See the diagram. 2. Why was the beaker raised up

on rocks?a. to make the Elodea closer to the

lightb. so you could better see what

happenedc. to make sure the Elodea did

not touch to tank bottomd. so water could escape from

thebeaker

Gina was trying to model the flow of energy through an oceanecosystem by using the pond behind their house. She observed fish,algae, water plants, frogs, aquatic insects, and variousmicroorganisms living in the pond. She wants to order the organismsof her pond by how energy flows through them. Which would be themost correct ordering?

a. water plants → frogs → insects → fishb. algae → microorganisms → insects → fishc. fish → water plants → frogs → microorganismsd. algae → fish → frogs → microorganisms

YearYear RabbitsRabbits LynxLynx

19981998 100100 33

19991999 180180 33

20002000 200200 44

20012001 225225 66

20022002 8080 66

20032003 6060 22

20042004 120120 22

20052005 200200 33

20062006 190190 55

Graph the following data and use your graphs to answer the following questions.

1) How many rabbits can the habitat support?

2) List three factors that could have caused the changes in rabbit population.

3) What relationship exists between the rabbit and the lynx?

4) Predict how the introduction of sheep into this habitat would influence the rabbit population. Justify your predictions.

→ → →

What is missing in the above model of a food chain?

a. a mouse because an owl eats itb. a tree because it is larger than the plant shownc. a deer because it eats the grassd. a hawk because it is a consumer

Key:a. Problem (stated or implied)b. Hypothesis (possible solution to the problem)c. Statement of initial observations.d. Observation based on the experiment (1) During some years when the annual rainfall was only 1.5 inches, the

desert floor in Death Valley bloomed with a carpet of color. (2) How can seeds measure the rainfall in Death Valley?

(3) In the laboratory, if seed-containing desert soil is spread on pure sand and wet with a sprinkler, the seeds will not germinate until the equivalent of one inch of rain has fallen on them.

(4) What factor(s) assure the germination of these desert plants?•

In a closed terrarium, more photosynthesis is taking place than respiration. Which gas would you expect to increase?

a. Airb. Carbon dioxidec. Oxygend. Nitrogen

Study the list below. Which sequence best shows the path of energy thatallows animals to move? Explain your reasoning.

a. photosynthesis --> light energy --> mechanical energy --> respirationb. mechanical energy --> light energy --> photosynthesis --> respirationc. light energy --> photosynthesis --> respiration --> mechanical energyd. respiration --> light energy --> photosynthesis --> mechanical energy

Rose Grass Hawk SnakeMushroom Antelope Cougar FrogMaple Tree Bacteria Aspen Tree Worms

Which organisms are decomposers?

Create a different foodchain for 3 food itemsthat you consumedyesterday.

Explain how different types of energy getconverted and passed through the food chain.