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Secondary sex characteristics are particularly evident in the sexually dimorphic phenotypic traits that distinguish the sexes of a species. [5] In evolution, secondary sex characteristics are the product of sexual selection for traits that show fitness, giving an organism an advantage over its rivals in courtship and in aggressive interactions. [6]
The Tanner scale (also known as the Tanner stages or sexual maturity rating (SMR)) is a scale of physical development as pre-pubescent children transition into adolescence, and then adulthood. The scale defines physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts ...
Male primary sex characteristics are the penis, the scrotum and the ability to ejaculate when matured. Female primary sex characteristics are the vulva, vagina, uterus, fallopian tubes, cervix, and the ability to give birth and menstruate when matured. [1] Hormones that express sexual differentiation in humans include: estrogens such as estradiol.
Puberty leads to sexual dimorphism through the development of the secondary sex characteristics, which further distinguish the sexes. On average, females begin puberty around age 10½ and complete puberty at ages 15-17; males generally begin puberty around ages 11-12 and complete puberty at ages 16-17.
Secondary sexual characteristics are traits that distinguish the two sexes of a species, but that are not directly part of the reproductive system. Some have argued that in general they evolved to give an individual an advantage over its rivals in courtship. They are opposed to the primary sexual characteristics: the sex organs .
Sex differences in human physiology are distinctions of physiological characteristics associated with either male or female humans. These differences are caused by the effects of the different sex chromosome complement in males and females, and differential exposure to gonadal sex hormones during development. Sexual dimorphism is a term for the ...
Precocious puberty. In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. There is early development of secondary sex characters and gametogenesis also starts earlier.
Sex differences in humans have been studied in a variety of fields. Sex determination generally occurs by the presence or absence of a Y chromosome in the 23rd pair of chromosomes in the human genome. Phenotypic sex refers to an individual's sex as determined by their internal and external genitalia and expression of secondary sex characteristics.