The phrase "take responsibility" means to accept the negative consequences of a mistake. In other words, if there's a problem, you either fix it yourself or

"Take responsibility" is used in the following ways:

• take responsibility for (oneself)

  You've got to start to take responsibility for yourself!

• take responsibility for (one's actions)

  You need to learn to take responsibility for your own mistakes.

• take responsibility for (doing something wrong)

  I think that, if anyone, Amy should be the one to take responsibility for losing the account.

• take full responsibility

  Please forgive me. I take full responsibility.