MED
Which role of protists has the most positive effect on maintaining the plant population in an ecosystem?
MED
Saprophytes are fungi that feed on dead and decomposing organisms. They secrete enzymes that digest components of cell walls, such as cellulose and lignin.
Which statement explains why these fungi are an important part of the biogeochemical cycle?
MED
Which statement best describes how bacteria recycle matter in an ecosystem?
MED
A student sets up a compost bin outdoors. Inside the bin microorganisms convert the student's vegetable and paper scraps into rich fertilizer.
Which of the following best describes the role that these microorganisms play in natural habitats?
HIGH
What would be the most likely effect of a wildfire that burned a large area of a forest?
MED - STAAR 2021 #32
Which statement is an example of how carbon moves through a food chain as part of the carbon cycle?
MED - STAAR 2022 #24
Students design an experiment to model the carbon cycle. The student combined the water and carbon dioxide-producing disks in a sealed flask. The flask represented Earth's atmosphere, and the lamp represented the sun. Their design is shown.
Which component can be added to the flask to reduce the concentration of carbon dioxide in the model atmosphere created by the disks?
HIGH - STAAR 2023 #25
When sawdust is added to soil, organisms in the soil will use all the available nitrogen to break the sawdust down.
What effect will the lack of nitrogen have on the plants that are near the sawdust?
HIGH
The city of Houston has several major highways in the surrounding area. These highways have thousands of cars that burn gasoline every day. What is most likely the result of this on the carbon cycle?
HIGH - also overlaps with 13B
The Sam Houston National Forest is being deforested for lumber and paper products. What step of the carbon cycle will be most directly affected by this human activity?
MED - STAAR 2016 #48
Nitrogen is an essential component of all living things. However, atmospheric nitrogen is unavailable for organisms to use. Through various processes and chemical changes, nitrogen moves through the biosphere, atmosphere, and geosphere in different forms, making it available for all organisms. Atmospheric nitrogen is deposited in the soil and surface waters primarily through precipitation. Once in the soil, microorganisms break down the nitrogen into different forms, which is then taken up by plants. Nitrogen eventually makes its way back into the atmosphere.
What would happen within the nitrogen cycle if a bactericide, a substance that kills bacteria, was added to the soil?