Explain why chromosomes, not individual genes,
assort independently.

Chromosomes of the cell not individual genes assort independently because genes are present inside the chromosomes or in other words chromosome is madeup of genetic material.

Explanation:

Genes are the molecules which have data or information about the formation of proteins of the cell. During cell division chromosomes starts replication. After replication, mitosis occurs. Mitosis is a type of cell division in which a single parent cell is divided into two daughter cells. Due to replication, each daughter cell attain same number of chromosomes which is present in parent cell.

the endomembrane system i think