20. You have genetically engineered a yeast cell to make a protein that will ultimately be secreted from the cell. If all is functioning well, in which order (from first to last) do you expect to find the protein in the cell until it is secreted? A) rER-Golgi-secretory vesicle-environment B) rER- Golgi-sER-nucleus-environment C) nucleus-rER-Golgi-secretory vesicle- environment D) SER-Golgi- secretory vesicle environment T E) rER-secretory vesicle-Golgi-environment 21. Communication between animal cells is facilitated by A) tight junctions. B) gap junctions. C) adhesive junctions. D) plasmodesmata. E) both choices B and C 22. Which of the following is a phototroph? A) a tree B) a mushroom C) bacteria growing on decomposing matter D) an earthworm E) a person 23. In a chemical reaction, the standard free energy change (AG") is calculated to be 3.67 cal/mol. What can be said of the chemical reaction? A) The reaction is at equilibrium under standard conditions. gabi apparchus B) The reaction goes spontaneously to the right under standard conditions. C) The reaction is not spontaneous under standard conditions. D) Products predominate over reactants at equilibrium under standard conditions. E) There can be no reaction. 24. Which is true of heterotrophs? A) They capture light energy. B) They cannot be unicellular. C) They store energy in the form of heat. D) They can function as autotrophs in an emergency. E) They can obtain energy from consuming phototrophs.