Sex from sientific point of viewSex refers to the
male and
female duality of
biology and
reproduction,
a process in biological
DNA that dates back 4.6 - 3.5 billion years.
DNA links back in an unbroken series of sexual reproduction taking forward
information to present day. The somewhat similar term
gender has more to do
with
identity than biology. The concept is confined to
organisms that
reproduce sexually.
The female
sex is definitely defined as the one which produces the larger
gamete(i.e., reproductive cell) and which typically bears the offspring. The category
of
sex reflects the biological reproductive function, rather than sexuality or
other behaviors. In some animals,
sex may be assigned to specific structures
rather than the entire
organisms as some species, such as earthworms, are
normally hermaphroditic.
Sex in non-animal speciesPlants are generally
hermaphrodites, but this terminology
is quickly complicated by variations in the degree of sexuality.
As with animals, there are only two types of gametes. These
are generally called male and female based on their relative
sizes and motility. In flowering plants,
flowers bear the
gametes. In some cases, flowers may contain only one type of
gamete, while in others they may contain both.
In other varieties of multicellular life (e.g. the fungi
division, Basidiomycota), sexual characteristics can be much
more complex, and may involve many more than two sexes. For
details on the sexual characteristics of fungi, see:
Hyphaand
Plasmogamy.
Sex among humansIn humans,
sex is conventionally perceived as a dichotomous
state or identity for most
biological and
social purposes, such
that a person can only be
female or
male. However, when the
criteria generally used to define femaleness and maleness are
examined more closely, it becomes apparent that the assignment
or determination of '
sex' occurs at multiple levels.
Environmental, biological, social, psychological and other
factors are all believed to have some role in this process,
and the complex interaction of these factors is expressed in
the diversity of biological and psychosocial 'states' or levels
found amongst the human population. A significant fraction of
the human population simply does not correspond exclusively to
either 'female' or 'male' with regard to every level of
definition expressed in the following. This discordance
is discussed in more detail below.
This list outlines the major levels at which society currently
recognizes a difference between human females and males. Some
criteria are dichotomous and some, such as body size, exhibit
sexual dimorphism (i.e. characteristics which are
statisticallymore likely to be found in one
sex than the other). Some of the
levels are more amenable to
scientific study or measurement than
others; some are "imputed" or assigned to individuals by the
society of which they are members (e.g. whether human males must
wear trousers is a result of social
norms); and some seem to
be generated within each individual as a subjective identity
or drive.
The relationship between the various levels of biological
sexual differentiation is fairly well understood. Many of
the biological levels are said to
cause, or at least shape,
the next level. For example, in most people, the presence
of a
Y chromosome causes the gonads to become testes, which
produce
hormones that cause the internal and external
genitalia to become male, which in turn lead parents to
assign 'male' as the
sex of their child (assigned
sex), and
raise the child as a boy (gender of rearing). However, the
degree to which biological and environmental factors contribute
to the psychosocial aspects of sexual differentiation, and
even the interrelationships between the various psychosocial
aspects of differentiation, is less well understood (see the
nature versus nurture debate).
See also-
Evolution of sex-
Human sexuality-
List of gender names-
Mammalian gestation-
Sex game-
Sexual differentiation-
Anal sex-
Sex toys-
Sex ratioIf you liked this article, contact me on ICQ, write me email or visit
my site about scientifical intelligence of
sex.
Deribo.
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