The number of chromosomes in a human secondary oocyte is

Explanation

The first meiotic division is completed before ovulation and halves the chromosome number, so the secondary oocyte is haploid with 23 chromosomes, each still made of two chromatids. Forty six is the diploid number of the primary oocyte and of every body cell, which is why it is the common error. The second division is completed only if a sperm actually penetrates the egg.