1 1Carbon dioxide enters the leaves of plants and is used by the plant during photosynthesis to make — Anitrogen. Bhydrogen. Cglucose. Dwater. 2What role do decomposers have in contributing to the survival of other organisms in their environments? Decomposers — Ause sunlight to make food for other organisms Brelease nutrients that plants use into the soil. Cexhale oxygen through the process of respiration. Dgive off water vapor into the air during transpiration. Cycling of Matter Matter and Energy

2 3Look at the chart provided. For each temperature and over each one week time period, determine the one week time period where the greatest decomposition of matter occurred. Record the height of the pile of leaves after undergoing its greatest decomposition. Record your answer in the grid provided. Cycling of Matter Matter and Energy Temperature °C Week 1 Height of a pile of leaves (cm) Week 2 Height of a pile of leaves (cm) Week 3 Height of a pile of leaves (cm) Week 4 Height of a pile of leaves (cm) 20° C ° C

3 Cycling of Matter Matter and Energy 4Which of the following organisms is responsible for the decomposition of organic matter in a forest? AInsects BBacteria CBushes DRabbits 5Which of the following describes an example of biomass decay in a habitat? ABacteria break down dead plants and add nutrients to the soil BMountain lions hunt and kill smaller mammals to get energy CPlants use sunlight to produce glucose during photosynthesis DHot and cold temperatures weather and break down rocks

4 6What type of energy is released as decomposition takes place in a compost bin? ALight BNuclear CHydroelectric DThermal Cycling of Matter Matter and Energy 7Nitrogen from living organisms is returned to the atmosphere by the action of — Aautotrophs such as algae. Bconsumers such as animals. Cdecomposers such as bacteria. Dproducers such as green plants.

5 8 The graph shows the temperatures in a classroom compost bin for eight weeks. During which time period was the most decomposition occurring? ADuring Week 1 BDuring Week 2 CDuring Week 3 DDuring Week 4 Cycling of Matter Matter and Energy

6 9During decomposition, bacteria in the soil — Achange nitrogen into a useful form Bremove carbon from the atmosphere. Ccause weathering of rocks and minerals. Dproduce sugars that animals can ingest. Cycling of Matter Matter and Energy 10Some students used the setup shown to model the cycling of water in a habitat. In the model, which part of a natural habitat is represented by the water droplets collecting on the bottom of the pan? ASun’s thermal energy drying up a lake BMoisture given off by plants through leaves CRain, snow, and other forms of precipitation DThe formation of clouds in the atmosphere