Final answer:
An XY individual without a functional SRY gene will develop female reproductive anatomy because the SRY gene is essential for initiating male sex development. Without this gene, the default female developmental pathway is followed, resulting in the formation of female gonads and reproductive structures.
Step-by-step explanation:
An XY individual missing the SRY gene will develop female reproductive anatomy due to the absence of this critical sex-determining component. During fetal development, the default pathway leads to the formation of female characteristics. In normal male development, the SRY gene on the Y chromosome kicks off a cascade of genetic events leading to the suppression of female structures and the stimulation of male sex organ development. However, with a nonfunctional or absent SRY gene, this cascade does not occur, and the individual's reproductive system develops into female structures instead because the body does not receive the 'signal' to develop male characteristics.
In the context of an embryo with XY chromosomes, without the effect of the SRY gene, cells that could become either male or female gonads—the bipotential gonadal tissue—will follow the pathway to become ovaries instead of testes. This is because SRY is predominantly responsible for testes formation and inhibition of ovarian development. Accordingly, the individual will exhibit female reproductive anatomy despite having an XY karyotype.