Question

Which of the following is NOT a genetic mechanism for sex determination?

a. There are two sex chromosomes, W and Z, and ZZ results in a male and ZW results in a female.
b. Fertilized eggs develop into females, and unfertilized eggs develop into males.
c. Eggs incubated at higher temperatures develop into females, and eggs incubated at lower temperatures develop into males.
d. Individuals with two sex chromosomes are female, and individuals with one sex chromosome are male.

Answer 1

The statement that is NOT a genetic mechanism for sex determination is d. Individuals with two sex chromosomes are female, and individuals with one sex chromosome are male.

Step-by-step explanation:

The correct answer to the question of which of the following is NOT a genetic mechanism for sex determination is: d. Individuals with two sex chromosomes are female, and individuals with one sex chromosome are male. This assertion is not applicable to the standard genetic systems for determining sex in either mammals or birds. In mammals, sexual differentiation is typically governed by the XX/XY system; individuals with two X chromosomes (XX) are female and individuals with one X and one Y chromosome (XY) are male. Contrary to the claim in option d, no mammalian males have just one sex chromosome in natural conditions.

On the other hand, option b does not reflect a chromosomal sex-determination system but rather a form of environmental sex determination which occurs in some reptiles; not all organisms utilize such a system. Finally, option c again is describing environmental sex determination and also does not apply to all organisms.