Answer:
12 chromosomes
Step-by-step explanation:
Mitosis is a type of cell division that involves the formation of two genetically identical daughter cells. The two daughter cells are genetically identical in the sense that they contain the same number of chromosomes as the parent cell. Mitosis involves four stages namely: Prophase, Metaphase, Anaphase and Telophase.
In the metaphase stage as stated in this question, homologous chromosomes align at the equator of the cell called cell plate, before each chromatids are pulled apart by microtubules at the Anaphase stage.
According to the question, the spider being worked on has 6 pairs of chromosomes, which will align at the cell's equator during metaphase stage of mitosis. Since the replicated chromosomes (chromatids) are yet to separate to opposite poles of the cell, the cell will still contain 12 chromosomes at the metaphase stage.
N.B: Each chromosome contains 2 chromatids or replicated chromosome, which will be separated at the Anaphase stage. Each chromatid will be an individual chromosome after cytokinesis.