Video Transcript
At what stage in life do the
majority of secondary sexual characteristics most commonly appear? During infancy, during adulthood,
during puberty, or during old age.
Let’s approach this question by
first defining the key term secondary sexual characteristic so we can figure out
when they will appear in humans. Secondary sexual characteristics
are physically observable traits that develop during a period in adolescence called
puberty and are not directly involved in reproduction. Secondary sexual characteristics
can be similar in both biological males and females, for example, growth of pubic
hair, but they often physically distinguish males from females. For example, usually only females
develop breasts that would be capable of producing milk after childbirth to feed a
newborn baby.
The release of high quantities of
sex hormones triggers the development of these secondary sexual characteristics. And different concentrations of
typically male and typically female sex hormones will determine the different
characteristics that appear in the two biological sexes. The release of high quantities of
these sex hormones begins to occur during a stage called puberty. Puberty is a stage in adolescence
when humans reach sexual maturity and become capable of sexual reproduction even if
they might not be emotionally or mentally ready for it yet. Therefore, the life stage at which
the majority of secondary sexual characteristics most commonly appear is during
puberty.
