Final answer:
A scientist cannot determine a person's sex by examining a skin cell. Biological sex is determined by analyzing chromosomes, DNA, hormones, and physical examination. XX individuals are typically female, while XY individuals are typically male.
Step-by-step explanation:
Sex determination is a complex process that involves the analysis of chromosomes and genetic factors. A scientist would not be able to determine if a person is male or female by examining a skin cell alone. The determination of biological sex requires the analysis of DNA, hormones, and physical examination. Chromosomes play a crucial role in determining sex, with XX individuals typically being female and XY individuals typically being male. However, it is important to note that there can be variations in sex determination due to genetic conditions.