حل أوراق عمل العلوم المتكاملة الصف السابع انسبير
حل أوراق عمل العلوم المتكاملة الصف السابع انسبير
Answer Key with Questions
SBQ2-Practise
1) Consumers produce their own food.
True
False
Correct Answer
False
2) Energy cycles through ecosystems because it returns to the Sun.
True
False
Correct Answer
False
3) Available energy increases as it is transferred from one organism to another in a food chain.
True
False
Correct Answer
False
4) ?Which of the following would eat a dead rabbit
carnivore
detritivore
herbivore
omnivore
Correct Answer
detritivore
5) ?Which of the following would eat a hamburger with lettuce on it
carnivore
detritivore
herbivore
omnivore
Correct Answer
omnivore
6)? Which of the following eats only eucalyptus leaves
carnivore
detritivore
herbivore
omnivore
Correct Answer
herbivore
7) ?Which is most likely the first step in a basic food chain
The snake obtains energy by eating the mouse.
Plants make energy-rich food using sunlight.
The Sun emits energy.
The hawk obtains energy by eating the snake.
Correct Answer
The Sun emits energy.
8) Which of the following organisms would NOT be in the first trophic level of an energy pyramid
dog
tree
grass algae
Correct Answer
dog
9)? Which is a model of feeding relationships
protein building
food map
food web
sugar molecules
Correct Answer
food web
10) ……As you move upward, from level to level, in an energy pyramid, available energy
decreases
increases
stays at the same level
is destroyed
Correct Answer
decreases
grass, the frog eats the cricket, and the snake eats the frog, each animal gets energy for life processes by breaking down food molecules. The grass, the cricket, the frog, and the snake all release energy as heat. When all these organisms die, the soil bacteria (decomposers) break down the carbon compounds in the organisms’ bodies to get energy for life processes. The soil bacteria (decomposers) also release heat as they use energy. The heat is not available to organisms in the ecosystem to use again for energy. This is why continual energy input from the Sun is necessary for the organisms in the ecosystem to live.
12) Elements such as oxygen, nitrogen, and carbon cycle through a system once.
True
False
Correct Answer
False
13) Nitrogen, as it is found in the atmosphere, can be used by plants and animals.
True
False
Correct Answer
False
14)? Which of the following does NOT move continuously through ecosystems
water
aluminum
energy
nitrogen
Correct Answer
aluminum
15) ?Which of the following is NOT part of the water cycle
nitrogen fixation
evaporation
condensation
precipitation
Correct Answer
nitrogen fixation
16)? Which of the following steps in the nitrogen cycle takes place after animals eat plants
Decaying waste returns nitrogen to the soil.
Bacteria on plant roots fix nitrogen to make it usable.
Plants use nitrogen from the soil.
Lightning changes nitrogen gas into nitrogen compounds.
Correct Answer
Decaying waste returns nitrogen to the soil.
17) ?Which of the following is NOT an example of how bacteria aid in the nitrogen cycle
nitrogen fixation
breaking down the tissue of dead organisms
changing nitrogen compounds into atmospheric nitrogen
infecting tissue
Correct Answer
infecting tissue
18) ?Phytoplankton are said to release how much of the oxygen in Earth’s atmosphere
between 5% and 10%
between 15% and 20%
less than 5%
more than 50%
Correct Answer
more than 50%
19) Which process can release carbon to the air and into the soil?
photosynthesis
decomposition
combustion
cellular respiration
Correct Answer
decomposition
20) ?Which of the following is NOT a way that carbon is stored in the environment as a fossil fuel
water
coal
oil
natural gas
Correct Answer
water
21) Describe the role of photosynthesis and cellular respiration in the carbon cycle. Then identify and describe the role these processes play in one other cycle of matter.
Correct Answer
.Answers may vary
Explanation
During photosynthesis carbon is removed from the atmosphere; during cellular respiration carbon is released into the atmosphere. Photosynthesis and cellular respiration also play a role in the oxygen cycle. During photosynthesis, oxygen is released into the atmosphere. During cellular respiration, oxygen is taken in from the atmosphere.
22) What happens to the parts of food molecules as matter moves through an organism
Correct Answer
.Answers may vary
Explanation
The parts of food molecules are rearranged to make new molecules or release energy.
23)? In what form is energy that is NOT used for life processes released from living things
light energy
sound energy
thermal energy
chemical energy
Correct Answer
thermal energy
24) Why are food webs better representations of how energy moves through an ecosystem than food chains
Food chains include decomposers, which do not play a role in energy movement through an ecosystem.
Food chains show how matter moves through an ecosystem, not not energy.
Food webs include how energy enters an ecosystem, and food chains don’t.
Food webs show that animals in an ecosystem can get energy by eating different things.
Correct Answer
Food webs show that animals in an ecosystem can get energy by eating different things.
25) Use the figure to answer the following questions
?Which organism has the most energy available in the food web shown
diatoms
squid
leopard seal
orc
Correct Answer
diatoms
26) Use the figure to answer the following questions
?In the food web, what eats the squid
diatoms
squid
leopard seal
orca
Correct Answer
leopard seal
27)?How does the movement of water in ecosystems differ from the movement of energy
Correct Answer
.Answers may vary
Explanation
.Water cycles through ecosystems in a continuous cycle. Energy flows in one direction
28). Describe the water cycle
Correct Answer
.Answers may vary
Explanation
Explanations will vary, but should include at least the minimum components of evaporation, condensation, and precipitation, and may include some of the lesser components, such as transpiration
29) The graphs show the atmospheric carbon dioxide (CO2) concentration at different times of the day and in different seasons of the year.
a. Explain the role of photosynthesis in relation to the amount of carbon dioxide in the atmosphere
b. Explain how each graph provides evidence that carbon dioxide is removed from the atmosphere by the process of photosynthesis
Correct Answer
.Answers may vary
Explanation
a. Photosynthesis is a process in which green plants (and other photosynthetic organisms) use energy from the Sun to make oxygen and food (sugars) from carbon dioxide and This process occurs during the day when the plants capture sunlight and take in carbon dioxide and water. When plants use carbon dioxide, they remove a great deal of this gas from the atmosphere.
b. Evidence of photosynthesis can be determined by looking at the amounts of carbon dioxide in the atmosphere during a day and during a year. If there is a greater amount at night than during the day, then it is highly likely that photosynthesis is taking place during the day. If there is more carbon dioxide in the atmosphere during the winter than in the summer, then it is likely that photosynthesis is taking place during the summer. Graph 1 shows more carbon dioxide during the night than during the day. Graph 2 shows more carbon dioxide in the winter than in the summer. Graph 1 indicates that low levels of carbon dioxide are evident in the day during photosynthesis and high levels are evident during the night when no photosynthesis is taking place. Graph 2 indicates that low levels of carbon dioxide are evident during the summer when photosynthesis and tree growth are taking place, and high levels are evident during the winter when little photosynthesis is taking place
30) .Several forest organisms make up the food web shown
a. Describe what needs to be added to this model to show how energy flows into and out of this food web.
.b. Explain how the model demonstrates the cycling of matter within the ecosystem
Explanation
a. The diagram needs to show energy input from the Sun into the plant, and heat loss from every organism.
b. When a member of an ecosystem dies, matter is returned to the soil and air by decomposers. This matter is used again by living organisms either as nutrients (minerals) in the soil or as molecules, such as carbon dioxide and oxygen, used in photosynthesis by plants and cellular respiration in both plants and animals. (The diagram also shows that when one organism eats another, matter is rearranged to form new molecules to support growth and cellular processes.)
31)? What is the source of the carbon atoms in a plant’s cells
they were created as the plant grew
the Sun
water molecules
the environment
Correct Answer
the environment
