A human zygote contains a total of 46 chromosomes. This is the result of the fusion of a sperm cell, which carries 23 chromosomes, and an egg cell, which also carries 23 chromosomes. When these gametes unite during fertilization, they form a zygote with a complete set of chromosomes, thus establishing the genetic blueprint for the developing organism.
The chromosomes in a zygote are organized into 23 pairs, with one chromosome of each pair inherited from the mother and one from the father. This diploid number of 46 is vital for normal human development, as it ensures that the zygote has the correct genetic information to grow into a fully functioning individual.