1. The nerve carrying messages from the eye to the brain is the _______ nerve.   olfactory   auditory   optical   Hint Half-n-half Clue   2. _______ animals spend much of their time in air.   Arboreal   Aquatic   Aerial   Half-n-half Clue   3. _______ is a unicellular animal.   Chlamydomonas   Amoeba   Spirogyra   Half-n-half Clue   4. The nerve carrying messages from the tongue to the brain is the _______ nerve.   olfactory   auditory   gustatory   Half-n-half Clue   5. _______ animals live in water.   Aquatic   Aerial   Arboreal   Half-n-half Clue   6. _______ animals live on trees.   Arboreal   Aerial   Terrestrial   Half-n-half Clue   7. The nerve carrying messages from the nose to the brain is the _______ nerve.   gustatory   olfactory   auditory   Half-n-half Clue