To enter and exit a cell, molecules often travel across the membrane via transmembrane proteins. Some of these proteins are active, some are passive. From the following transmembrane proteins, which one is active?

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above

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

Which of these parts of the membrane large moecules pass through it ?