Question

An embryo with the genotype XX develops female accessory sex organs becat a. androgens. b. estrogens. c. lack of androgens. d. lack of estrogens.

Short answer

An embryo with the genotype XX develops female accessory sex organs because of estrogens.

Step-by-step solution

Understand the XX Genotype

An embryo with the XX genotype is genetically female. The presence of two X chromosomes in an individual determines the development of female primary sex characteristics (ovaries) and secondary sex characteristics (female accessory sex organs).

Role of hormones in sex determination

Hormones play an essential role in sex determination and the development of sex organs. Androgens and estrogens are the primary sex hormones responsible for the development of male and female characteristics, respectively. Androgens (such as testosterone) are responsible for the development of male characteristics, while estrogens (such as estradiol) are responsible for the development of female characteristics.

Identify the correct choice

Now, let's analyze the given choices: a. Androgens: As mentioned earlier, androgens are responsible for the development of male characteristics, not female ones. b. Estrogens: Estrogens are responsible for the development of female characteristics, so this choice seems to be correct. c. Lack of androgens: Although the lack of androgens can prevent the development of male characteristics, it may not necessarily lead to the development of female characteristics. However, this choice is closely related to the correct option and can be considered a partial answer. d. Lack of estrogens: If there is a lack of estrogens, that would inhibit the development of female characteristics rather than promote it. Considering these explanations, the correct choice is: b. Estrogens.

Key concepts

XX Genotype

The XX genotype plays a crucial role in determining the genetic sex of an embryo. This genotype consists of two X chromosomes, which defines an individual as genetically female.
The presence of the XX genotype signals the body to develop female primary sex characteristics, such as ovaries, during the embryonic stage. These characteristics are essential for the production of eggs and the secretion of certain female hormones.
Once these primary characteristics are established, they lay the groundwork for the development of secondary sex characteristics, such as female accessory sex organs. Understanding the basics of the XX genotype helps in grasping why specific hormones and organs develop in a female embryo.

Female Accessory Sex Organs

Female accessory sex organs are an important part of the reproductive system. They support reproduction and include structures beyond the primary reproductive organs, like ovaries.
In an embryo with an XX genotype, these organs develop under the influence of hormones, although their foundational structure is laid out genetically. Key female accessory sex organs include:

• Uterus: The muscular organ where a fertilized egg can develop into a fetus.
• Fallopian Tubes: Pathways that enable eggs to travel from the ovaries to the uterus.
• Vagina: A canal that acts as a conduit from the external genitalia to the uterus.

Understanding these organs and their development is crucial for studying female reproductive health.

Androgens and Estrogens

Hormones and their unique roles are pivotal in the process of sex determination. Two key hormones frequently discussed are androgens and estrogens.
Androgens, such as testosterone, primarily influence the development of male traits. They don’t play a role in developing female sex characteristics but are vital for male traits like body hair and increased muscle mass.
On the other hand, estrogens play a significant part in the development of female secondary sex characteristics, such as the growth of female accessory sex organs. Estrogens like estradiol are vital for processes like the development of the uterine lining and the regulation of the menstrual cycle.
Understanding the balance and function of these hormones helps us appreciate how the body differentiates and maintains male and female traits.