TALKING ABOUT EXTRACTING DNA

eXPERIMENT: MASH FRUIT UP WITH COLD ISOPROPYL ALCOHOL, SALT, WATER, AND DETERGENT THEN EXTRACT DNA USING A WOODEN SPLINT.

WHEN EXTRACTING DNA FROM STRAWBERRIES WHY CAN WE NOT SEE IT IN MASHED UP STRAWBERRIES BUT YOU CAN SEE IT ON A WOODEN SPLINT? WHY DID ALCOHOL NEED TO BE COLD AND WHY DID WE HAVE TO POUR ALCOHOL SLOWLY DOWN INTO MASHED STRAWBERRIES?
i'M NOT SURE HOW TO ANSWER THESE QUESTIONS....HELP!!!