Everything about Male totally explained
Male (♂) refers to the sex of an organism, or part of an organism, which produces small mobile
gametes, called
spermatozoa. Each spermatozoon can fuse with a larger
female gamete or
ovum, in the process of
fertilization. A male can't reproduce
sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually.
Not all species share a common
sex-determination system. In humans and most animals, sex is determined
genetically but in other species it can be determined due to social, environmental, or other factors. The existence of two sexes seems to have been selected independently across different
evolutionary lineages (see
Convergent Evolution). Accordingly, sex is defined
operationally across species by the type of gametes produced (ie: spermatozoa vs. ova) and differences between males and females in one lineage are not always predictive of differences in another.
Male/
Female dimorphism between organisms or reproductive organs of different sexes isn't limited to animals; male gametes are produced by
chytrids,
diatoms and land
plants, among others. In land plants,
female and
male designate not only the female and male gamete-producing organisms and structures but also the structures of the
sporophytes that give rise to male and female plants.
Anatomy
All males, regardless of independent origin, kingdom, or other
phylogenetic subdivision, share at least the anatomy to produce male gametes. Some have sophisticated
organs and
organ systems designed to produce, dispense, and deliver the gamete to a location suitable for ovum fertilization.
Even where structures and cell types have arisen independently, "
sperm" is ordinarily used to refer to the male gamete. Among animals that undergo
internal fertilization, "
penis" is often used to refer to an organ inserted into the female for
insemination. This process is called reproduction
sex.
Symbol
A common
symbol used to represent the male gender is the
Mars symbol,
♂ (
Unicode: U+2642
Alt codes: Alt+11)—a circle with an arrow pointing
northeast. This is often called a stylized representation of the
Roman god Mars' shield and spear. Also, this symbol is found on the logo of the popular automobile manufacturer
Volvo.
Sex determination
The sex of a particular organism may be determined by a number of factors. These may be genetic or environmental, or may naturally change during the course of an organism's life. Although most species with male and female sexes have individuals that are either male or female,
hermaphroditic animals, such as
worms, have both male and female reproductive organs.
Genetic determination
Most
mammals, including
humans, are genetically determined as such by the
XY sex-determination system where males have an XY (as opposed to XX) sex
chromosome. It is also possible in a variety of species, including human beings, to be XXY or have other intersex/hermaphroditic qualities. These qualities are widely reported to be as common as redheadedness (about 2% of the population). During
reproduction, a male can give either an X sperm or a Y sperm, while a female can only give an X egg. A Y sperm and an X egg produce a
boy, while an X sperm and an X egg produce a
girl. The
ZW sex-determination system, where males have a ZZ (as opposed to ZW) sex chromosome may be found in
birds and some
insects (mostly butterflies and moths) and other organisms. Members of
Hymenoptera, such as
ants and
bees, are determined by
haplodiploidy, where most males are
haploid and females and some sterile males are
diploid.
Environmental determination
In some species of reptiles, including
alligators, sex is determined by the temperature at which the egg is incubated. Other species, such as some
snails, practise sex change: adults start out male, then become female. In tropical
clown fish, the dominant individual in a group becomes female while the other ones are male.
In some
arthropods, sex is determined by infection.
Bacteria of the genus
Wolbachia alter their sexuality; some species consist entirely of ZZ individuals, with sex determined by the presence of
Wolbachia.
Secondary sex characteristics
In those species with two sexes, males may differ from females in ways other than production of spermatozoa. Males are generally smaller than females in seed plants (the
pollen grain is the male plant) and many fishes and birds, but larger in many mammals, including humans. In birds, the male often exhibits a colorful
plumage that attracts females.
Further Information
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