All cells in the human body start with 46 chromosomes. This is referred to as the diploid number.

* These chromosomes are arranged in 23 pairs, with one chromosome from each pair coming from the mother and the other from the father.

* This initial number of chromosomes is maintained in most cells through mitosis (cell division).

* However, sex cells (sperm and egg) undergo meiosis, a process that reduces the chromosome number to 23, called the haploid number. This ensures that when a sperm and egg combine during fertilization, the resulting zygote has the correct diploid number of 46 chromosomes.