8. how do nitrogen-fixing bacteria cycle nitrogen through ecosystems? (1)
a. they release nitrogen into the atmosphere when they replicate their dna .
b. they convert sunlight into chemical energy which is then stored in the nitrogen.
c. they convert ammonia from animal feces and urine into forms that plants can use.
d. they capture nitrogen from the atmosphere and convert it into forms that plants can use

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?

What is the main function of the central vacuole in a plant cell? a. absorbs energy from the sun to produce food b. holds water and maintains turgor pressure c. breaks down molecules to release energy d. contains the cell's genetic material

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a.coral reefs because of the loss of the symbiotic algae living within their bodies b.penguin populations because the fish they eat will move into warmer waters c.mountain-dwelling birds because rising sea levels will relocate their food sources d.large cats in the rainforest because of decreased habitat loss for their prey