How would add an scene on the Countdown Timer

I need to know where I should add an scene in my Countdown Timer script . The purpose for having a scene for the player . If the player wins or lose . I also have and Score System script. Here are my scripts :

using UnityEngine;
using UnityEngine.UI;

public class MyClock : MonoBehaviour
{
public int Minutes = 0;
public int Seconds = 0;

  private Text    m_text;
  private float   m_leftTime;

  private void Awake()
  {
      m_text = GetComponent<Text>();
      m_leftTime = GetInitialTime();
  }

  private void Update()
  {
      if (m_leftTime > 0f)
      {
          //  Update countdown clock
          m_leftTime -= Time.deltaTime;
          Minutes = GetLeftMinutes();
          Seconds = GetLeftSeconds();

          //  Show current clock
          if (m_leftTime > 0f)
          {
              m_text.text = "Time : " + Minutes + ":" + Seconds.ToString("00");
          }
          else
          {
              //  The countdown clock has finished
              m_text.text = "Time : 0:00";
          }
      }
  }

  private float GetInitialTime()
  {
      return Minutes * 60f + Seconds;
  }

  private int GetLeftMinutes()
  {
      return Mathf.FloorToInt(m_leftTime / 60f);
  }

  private int GetLeftSeconds()
  {
      return Mathf.FloorToInt(m_leftTime % 60f);
  }

}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class ScoreManager : MonoBehaviour
{
public int currentScore = 0;
public Text text;
ScoreManager scoreManager;
void Start ()
{
text = GetComponent ();
currentScore = 0;
UpdateScore(0);
scoreManager = gameObject.GetComponent(); // this may not be exactly how you get a reference to ScoreManager

 }

 void UpdateScore(int score)
 {
     currentScore += score;
     if (text != null)
     {
         text.text = "Score :" + currentScore;
     }
  scoreManager.UpdateScore(100);
 }

}

Could it be that you worded that wrong. Because a scene is a SCENE like it has its own camera and light and gameObjects and whatnot…

Though if I understand it right, add the animation or Ui-elemts on line 23 when the clock run out of time. Since i gess you cant lose or win before times run out.