With pdo you would have:
$getStuff = $pdo->prepare('SELECT `question`, `answer` FROM `Quizzes` WHERE `questionNumber`< :questionNumber ORDER BY `questionNumber` ASC');
$getStuff->execute(array('questionNumber' => 21);
$rows = $getStuff->fetchAll();
foreach($rows as $row)
{
$questions[] = $row['question'];
$answers[] = $row['answer'];
}
It's up to you to decide if removing the binding stuff makes the code any easier to read and maintain.