1. why do the receptor proteins need to be on the outside of the cell? 2. why can some molecules like water and glucose easily pass through the membrane but macro molecules like starch cannot?

What organ systems are working to you cool down after a workout?

Which of the organisms listed below performs nitrogen fixation? a. legumes b. plants c. bacteria d. fungi

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.