What is the diagram to the left called?

The diagram is called a karyotype. It shows the number and appearance of chromosomes in a cell. The last two chromosomes, listed X and Y, are sex chromosomes. XX is the genotype for a female and XY is the genotype for a male. This specific diagram shows the chromosomes of a male as it has XY.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.