Skin from male mouse grafted on back of female. within 2 wks graft becomes necrotic and must be removed. what cells responsible

The correct answer is CD8 + T lymphocytes.

This process is known as graft rejection and it is defined as the immunological destruction of transplanted organs or tissues. The graft rejection may be based on both cell-mediated and antibody-mediated immunity against cells of the graft. When rejection occurs via cellular immunity, it is mediated by killer T cells (cytotoxic or CD8 + cells) which induce the apoptosis of target cells.