using call_user_func_array() causing errors

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Errors appearing in mysqli code and call_user_func_array()

I am getting quite a few errors when trying to create a dynamic where clause using mysqli:

Warning: Parameter 2 to mysqli_stmt::bind_param() expected to be a reference, value given in ... on line 319

Warning: mysqli_stmt::execute(): (HY000/2031): No data supplied for parameters in prepared statement in ... on line 328

Im guessing there is a change that is needed to solve the problems but what happens is that if one of the two drop down menu's do not equal All or if both don't equal All then it comes up with the errors.

Below is the code display both the drop down menus and the query (with dynamic where clause) that follows depending n options selected:

PHP/MYSQLI:

  function StudentAnswers()
    {


/*BELOW IS THE QUERY WHERE I AM TRYING TO RETRIEVE DATA DEPENDING ON THE ASSESSMENT CHOSEN AND
THEN DEPENDING ON OPTIONS CHOSEN IN STUDENT AND QUESTION NUMBER DROP DOWN MENU */

    $selectedstudentanswerqry = "
    SELECT
    StudentAlias, StudentForename, StudentSurname, q.SessionId, QuestionNo, QuestionContent, o.OptionType, q.NoofAnswers, GROUP_CONCAT( DISTINCT Answer
    ORDER BY Answer SEPARATOR ',' ) AS Answer, r.ReplyType, QuestionMarks, 
    GROUP_CONCAT(DISTINCT StudentAnswer ORDER BY StudentAnswer SEPARATOR ',') AS StudentAnswer, ResponseTime, MouseClick, StudentMark
    FROM Student s
    INNER JOIN Student_Answer sa ON (s.StudentId = sa.StudentId)
    INNER JOIN Student_Response sr ON (sa.StudentId = sr.StudentId)
    INNER JOIN Question q ON (sa.QuestionId = q.QuestionId)
    INNER JOIN Answer an ON q.QuestionId = an.QuestionId
    LEFT JOIN Reply r ON q.ReplyId = r.ReplyId
    LEFT JOIN Option_Table o ON q.OptionId = o.OptionId
    ";

    // Initially empty
    $where = array('q.SessionId = ?');
    $parameters = array($_POST["session"]);
    $parameterTypes = 'i';

    // Check whether a specific student was selected
    if($_POST["student"] !== 'All') {
        $where[] = 'sa.StudentId = ?';
        $parameters[] = $_POST["student"];
        $parameterTypes .= 'i';
    }

    // Check whether a specific question was selected
    // NB: This is not an else if!
    if($_POST["question"] !== 'All') {
        $where[] = 'q.QuestionId = ?';
        $parameters[] = $_POST["question"];
        $parameterTypes .= 'i';
    }

    // If we added to $where in any of the conditionals, we need a WHERE clause in
    // our query
    if(!empty($where)) {
        $selectedstudentanswerqry .= ' WHERE ' . implode(' AND ', $where);
        global $mysqli;
        $selectedstudentanswerstmt=$mysqli->prepare($selectedstudentanswerqry);
        // You only need to call bind_param once
            call_user_func_array(array($selectedstudentanswerstmt, 'bind_param'),
            array_merge(array($parameterTypes), $parameters)); //LINE 319 ERROR 1
    }

//Add group by and order by clause to query
    $selectedstudentanswerqry .= "
      GROUP BY sa.StudentId, q.QuestionId
      ORDER BY StudentAlias, q.SessionId, QuestionNo
    ";

    // get result and assign variables (prefix with db)
    $selectedstudentanswerstmt->execute(); //LINE 328 ERROR 2

//bind database fields $selectedstudentanswerstmt->bind_result($detailsStudentAlias,$detailsStudentForename,$detailsStudentSurname,$detailsSessionId,$detailsQuestionNo, 
    $detailsQuestonContent,$detailsOptionType,$detailsNoofAnswers,$detailsAnswer,$detailsReplyType,$detailsQuestionMarks,$detailsStudentAnswer,$detailsResponseTime,
    $detailsMouseClick,$detailsStudentMark); //LINE 331 ERROR 3

//store results retrieved
    $selectedstudentanswerstmt->store_result(); //LINE 332 ERROR 4

//count number of rows retrieved
    $selectedstudentanswernum = $selectedstudentanswerstmt->num_rows();     

//output query
    echo "$selectedstudentanswerqry";

    }

    ?>