Transcript a. to make the Elodea closer to the light b. so you could better see

Basketball
8th Grade Science
Mr. Olsen
Rose
Mushroom
Maple Tree
Grass
Hawk
Snake
Antelope
Cougar
Frog
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
decrease
b. if there were more sheep, then the wolf kills would increase
c. if there were fewer rabbits, then there would be fewer wolves around
d. if there were more rabbit food, then there would be more rabbits
Elodea is an underwater plant. A
Goodly sample of Elodea is placed
under a graduated glass beaker
under a bright light. The glass
beaker is balanced even on 3
identical rocks so it is off the floor of
the tank. See the diagram.
1.
What would you expect to see
after 20 minutes?
a. a gas will collect in the beaker
b. the Elodea will shrivel
c. bubbles will come out of the beaker
d. the Elodea will turn a darker green
Rose
Mushroom
Maple Tree
Grass
Antelope
Bacteria
Hawk
Cougar
Aspen Tree
Snake
Frog
Worms
• Which organisms are producers?
1) Which substances are the products of
photosynthesis?
a.
b.
c.
d.
carbon dioxide and oxygen
carbon dioxide and water
glucose (sugar) and oxygen
glucose (sugar) and water
1. Which level of the food pyramid
contains the most energy?
a. A
b. B
c. C
d. D
2. In what main form is energy lost
as you move up the pyramid?
a. light energy
b. chemical energy
c. heat energy
d. 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.
b.
c.
d.
Humans cannot survive without water.
Doctors tell us both plants and humans need sunlight.
Plants use carbon dioxide and water to photosynthesis.
Plants give off oxygen during photosynthesis.
Elodea is an underwater plant. A
goodly sample of Elodea is placed
under a graduated glass beaker
under a bright light. The glass
beaker is balanced even on 3
identical rocks so it is off the floor
of the tank. See the diagram.
2. Why was the beaker raised up
on rocks?
a. to make the Elodea closer to the
light
b. so you could better see what
happened
c. to make sure the Elodea did
not touch to tank bottom
d. so water could escape from
the
beaker
Gina was trying to model the flow of energy through an ocean
ecosystem by using the pond behind their house. She observed fish,
algae, water plants, frogs, aquatic insects, and various
microorganisms living in the pond. She wants to order the organisms
of her pond by how energy flows through them. Which would be the
most correct ordering?
a.
b.
c.
d.
water plants → frogs → insects → fish
algae → microorganisms → insects → fish
fish → water plants → frogs → microorganisms
algae → fish → frogs → microorganisms
Graph the following data and use your graphs to answer the following questions.
Year
Rabbits
Lynx
1998
100
3
1999
180
3
2000
200
4
2001
225
6
2002
80
6
2003
60
2
2004
120
2
2005
200
3
2006
190
5
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.
b.
c.
d.
a mouse because an owl eats it
a tree because it is larger than the plant shown
a deer because it eats the grass
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.
b.
c.
d.
Air
Carbon dioxide
Oxygen
Nitrogen
Study the list below. Which sequence best shows the path of energy that
allows animals to move? Explain your reasoning.
a.
b.
c.
d.
photosynthesis --> light energy --> mechanical energy --> respiration
mechanical energy --> light energy --> photosynthesis --> respiration
light energy --> photosynthesis --> respiration --> mechanical energy
respiration --> light energy --> photosynthesis --> mechanical energy
Rose
Mushroom
Maple Tree
Grass
Antelope
Bacteria
Hawk
Cougar
Aspen Tree
Snake
Frog
Worms
Which organisms are decomposers?
Create a different food
chain for 3 food items
that you consumed
yesterday.
Explain how different types of energy get
converted and passed through the food chain.