Question

The sex of an individual is best defined by:

a. their number of sex chromosomes.
b. sexual phenotype, such as size of gametes.
c. the ploidy of their body cells.
d. the presence or absence of a Y chromosome.
e. their behavioral characteristics.

Answer 1

The presence or absence of a Y chromosome is the most accurate genetic factor that determines the biological sex of an individual.

Step-by-step explanation:

The sex of an individual is best defined by the presence or absence of a Y chromosome. In humans, each body cell contains 23 pairs of chromosomes, including one pair of sex chromosomes, which are XX in females and XY in males. This chromosomal configuration is pivotal in determining the biological sex of an individual. While behavioral characteristics and sexual phenotype can be associated with sex, they are influenced by both genetics and the environment and are not definitive indicators of an individual's sex. Instead, the presence of the Y chromosome, which only occurs in males, is the most conclusive genetic factor in determining sex.