Chapter 17, End of Chapter, Review Questions, Exercise 1

The difference between males and females can be identified based on their difference in the reproductive organs, physical appearance, and androgen insensitivity syndrome. The various biological/behavioral test can be done to differentiate of the following basis:

1. Reproductive organs

Males: The male reproductive system consists of the testes, epididymis, ductus deferens, and the urethra. Accessory glands include the seminal vesicles, the prostate gland, and the bulbourethral glands. 

Females: The female reproductive system consists of ovaries, uterine tubes, uterus, vagina, and external genital organs. These differences between the male and the female reproductive structures can be used for biological differentiation. 

2. Physical characteristics

There is a difference in physical appearance between male and females. Females show the presence of prominent mammary glands which is redundant in males. Some of the differences are due to the variation in sex hormones between males and females. The male sex hormone is testostrone and the female sex hormone is estrogen. These hormones influence the body hair pattern and the musculature. The presence of body hair is more in males than females. The muscular development of males is more in males than in females. 

3. Karyotype 

Karyotype is the representation of all the chromosomes in humans. Humans contain 23 pairs of chromosomes. Out of these, 22 pairs are of autosomes that are similar in both male and female. The remaining one pair are the sex chromsomes. The sex chromsomes in male are XY and that in female are XX. This can be determined by the karyotype display of the chromosome. 

4. Androgen sensitivity syndrome

Such males show the presence of both X and Y chromosomes but the androgen receptor site is affected. The androgen receptor gene is located on the X chromosome. A defect in the gene results in lowered androgen sensitivity. Although the cells produce enough testosterone, the target cells do not respond. Hence, such an individual shows incompletely descended testis. The reproductive organs will be of a female because the testosterone receptors are defective. In such a person a test can be done to detect androgen sensitivity. 

5. Behavioral test 

A difference is seen in the case of males and females due to the variation in cognitive behavior. Men perform better at logical skills like reasoning. Women are more emotional and are good at writing skills. Men are more outwardly in courageous activities, whereas women are more caring in nature. However, these behaviors are generalized but vary from person to person.