The following sentence is inaccurate, but it can be made accurate by exchanging two words within it (forms of articles may need to change to accommodate word switches):

Question

The slow block to polyspermy is a physical envelope mediated by Ca2+ ions that cause cortical granules to fuse with the egg cell membrane, releasing compounds that cause the vitelline envelope to turn into a hardened fertilization reaction.
blank1 - Word Answer


blank2 - Word Answer

Answer 1

The block to polyspermy is a slow physical envelope mediated by Ca2+ ions that cause cortical granules to fuse with the egg cell membrane, releasing compounds that cause the vitelline envelope to turn into a hardened fertilization reaction.

blank1: Slow -> Physical
blank2: Physical -> Slow