Which of the following must be true for diffusion to occur? Molecules or particles must have different sizes.

Special protein channels must always be available.

There must be areas of different concentrations.

Energy must be available.

Question 4 using myplate's daily food plant for 2000 kilocalories as a reference, the servings from the protein foods group in this menu are a. adequate overall, and consistent with the dietary guidelines 2010 recommendations. b. short 2 ounce equivalents. c. inadequate in terms of the recommendations for a 2000 kcal diet. d. adequate overall, but inconsistent with the dietary guidelines 2010 recommendations.

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?

Onsider the paragraph above. what is one chemical property of water? a) water is a polar molecule. b) water is the universal solvent. c) water reacts with group 1 metals. d) water has a high specific heat capacity.