Final answer:
The impact of a drug that degrades DHT on the sex phenotype of an XY embryo is false because such an effect is stage-dependent, with the most significant changes occurring around the seventh week of gestation when male genitalia develop.
Step-by-step explanation:
The statement "A drug given to a pregnant person that degrades DHT would impact the sex phenotype of the embryo regardless of what stage of gestation it is administered" is false. DHT, or dihydrotestosterone, plays a significant role in the development of male sex characteristics in an embryo with XY chromosomes. When the androgen receptor is functional, DHT binds to it, initiating the development of male external genitalia. If DHT is degraded or if the androgen receptor function is completely ablated, an embryo with XY chromosomes will develop in a way that is more typical of female external genitalia despite having male (XY) chromosomal sex.
However, this impact on sex phenotype is stage-dependent. The critical period for male genital development is generally around the seventh week after conception, when testes begin to form due to the actions of the SRY gene on the Y chromosome. Therefore, affecting DHT levels or androgen receptor function after this critical period would not necessarily change the sex phenotype that has already been determined.