How many chromosomes are found in the organism that results from the union of a human sperm cell and an egg cell?

A human has a total of 46 chromosomes (23 from daddy and 23 from mommy). :)
A sperm cell has 23 chromosomes and an egg cell that has 23 chromosomes. 23 + 23 equals 46. Sometimes (due to mutations), a person
may have less chromosomes than they need. This may cause some problems like Turner syndrome(treatment can help aid the situation but, it can't be cured).
Hope this helps you :)