What type of gas do plants take in from the air to do photosynthesis?
a. carbohydrates
b. carbon dioxide
c. carbon gas
d. ammonia
b. carbon dioxide
Organic molecules, and all living organisms, are made of what element?
A. Carbon
B. Nitrogen
C. Water
D. Oxygen
A. Carbon
Where is most of the nitrogen found in?
Atmosphere
These organisms must obtain nitrogen from the food they eat.
A. Consumers
B. Producers
C. Plants
D. Bacteria
A. Consumers
Gases in the air that trap energy from the sun are called
a. acid rain
b. fossil fuels
c. global warming
d. greenhouse gas
d. greenhouse gas
Which of the following does not add carbon dioxide to the atmosphere?
a. cutting down trees
b. walking to school
c. driving a car
d. burning fossil fuels
b. walking to school
Animals get carbon from the plants through the _____________.
Food chain
What percentage of the Earth's atmosphere is nitrogen?
a. 50%
b. 78%
c. 21%
d. 90%
b. 78%
The process of plants absorbing nitrogen from the soil is called __________.
Assimilation
What do the arrows represent in a food chain or food web?
Energy flow - The arrows represent where energy goes to next.
Which process does not release carbon into the air?
a. burning fossil fuels
b. cellular respiration
c. photosynthesis
d. decomposition
c. photosynthesis
How have humans increased the amount of carbon in the atmosphere?
a. by burning oil
b. by using coal
c. by cutting down trees
d. all of the above
d. all of the above
What is the process where bacteria change ammonia into nitrites and nitrates?
a. nitrification
b. assimilation
c. nitrogen fixation
d. decomposition
a. nitrification
Why do biotic things of an ecosystem need nitrogen?
Nitrogen is needed to build proteins and DNA
Hawks eat snakes, snakes eat mice, and mice eat plants. What trophic level are the hawks in?
Tertiary consumer
Which part of the carbon cycle occurs when plants or animals die?
decomposition
Which part of the carbon cycle involves organisms breaking down food for energy and letting out carbon dioxide?
cellular respiration
The process of decomposers turning nitrates or nitrites into nitrogen gas which is then released into the atmosphere is called _________.
denitrification
During nitrogen fixation, bacteria in the roots of certain plants change nitrogen gas into what toxic type of nitrogen?
ammonia
Name the macromolecules that are organic.
How does deforestation increase the amount of carbon in the air?
Describe one way humans can prevent excess carbon from being released into the atmosphere.
1) Plant more trees. We cannot simply stop cutting trees because we need them for products.
2) Reduce the amount of energy we use so we are not dependent on fossil fuels
3) Use other sources of energy like wind, water, or solar, instead of using fossil fuels
Why are bacteria needed for the nitrogen cycle?
They turn nitrogen gas that is unusable to organisms into usable forms like ammonia, nitrites, and nitrates.
What is the correct order of the nitrogen cycle?
Use all of the following words: assimilation, food web, denitrification, nitrogen fixation, nitrification
nitrogen fixation, nitrification, assimilation, food web, denitirication
plants -> mice -> snakes -> hawks
If the snakes contain 25.5 kcal, how much available energy is in the plants?
Answer: the plants have 2,550 kcal
snakes = 25.5 kcal
mice = 255 kcal
plants = 2,550 kcal