Answer
This can be explained by the protein compound M-cdk. The cell's mitotic spindle will start in the presence of M-cdk.
Work Step by Step
M-cdk is a protein compound found in the cytoplasm of mitotic cells, as it induces the mitotic wheel. This means that any cytoplasm taken from a cell in the M phase will carry M-cdk in the cytoplasm. Knowing that M-cdk launches cells into the M phase, it makes sense that having an oocyte injected with cytoplasm containing M-cdk would push the cell into the M phase.
