The haploid number of chromosomes in humans is 23. This number represents the set of chromosomes that is found in gametes, which are the reproductive cells: sperm and egg.
In humans, we have 46 chromosomes in total, which are organized into 23 pairs. Each pair consists of one chromosome inherited from the mother and one from the father. When gametes are formed through a process called meiosis, the chromosome number is halved. Thus, each gamete contains just one set of chromosomes, which totals 23 chromosomes, making it haploid.
This reduction in chromosome number is essential for sexual reproduction because it ensures that when the sperm and egg unite during fertilization, the resulting embryo has the correct diploid number of 46 chromosomes.