After a major fire, grasses that are pioneer species start to grow in the ashy soil. The following list includes some of the ways that the grasses affect the ecosystem.
absorbing nutrients from the soil
absorbing water from the soil
providing food for animals
preventing erosion
Which of the items on the list contribute to ecological succession in the burned area?
A.
absorbing nutrients from the soil and providing food for animals
B.
preventing erosion and absorbing water from the soil
C.
absorbing nutrients from the soil and absorbing water from the soil
D.
preventing erosion and providing food for animals
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On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.