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The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical
organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized as parenchyma Parenchyma () is the bulk of functional ...
involved in
sexual reproduction Sexual reproduction is a type of reproduction Reproduction (or procreation or breeding) is the biological process Biological processes are those processes that are vital for an organism In biology, an organism (from Ancient Greek, ...
. Many non-living substances such as fluids,
hormone A hormone (from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is appr ...

hormone
s, and
pheromone A pheromone (from Ancient Greek ' "to bear" and hormone) is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the s ...

pheromone
s are also important accessories to the reproductive system. Unlike most
organ system An organ system is a biological system A biological system is a complex network Network and networking may refer to: Arts, entertainment, and media * ''Network'' (1976 film), a 1976 American film * ''Network'' (2019 film), an Indian film * ...
s, the
sex Sex is either of two divisions, typically male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete, or ovum, in the process of fertilization. A male cannot sexual r ...
es of differentiated
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...

species
often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the
offspring In biology, offspring are the young creation of living organisms, produced either by a Asexual reproduction, single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more ...

offspring
. Reproductive System 2001
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Animals

In mammals, the major organs of the reproductive system include the external
genitalia A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, ar ...

genitalia
(penis and vulva) as well as a number of internal organs, including the
gamete A gamete ( /ˈɡæmiːt/; from Ancient Greek Ancient Greek includes the forms of the Greek language Greek ( el, label=Modern Greek Modern Greek (, , or , ''Kiní Neoellinikí Glóssa''), generally referred to by speakers simply ...
-producing
gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are t ...
s (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable
sexually transmitted disease Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal disease, are infection An infection is the invasion of an organism's body tissues by disease-causing agents, th ...
s. Most other
vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic ma ...
s have similar reproductive systems consisting of gonads, ducts, and openings. However, there is a great diversity of physical
adaptation In , adaptation has three related meanings. Firstly, it is the dynamic evolutionary process that fits s to their environment, enhancing their . Secondly, it is a state reached by the population during that process. Thirdly, it is a or adapti ...

adaptation
s as well as
reproductive strategies
reproductive strategies
in every group of vertebrates.


Vertebrates

Vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an indiv ...
s share key elements of their reproductive systems. They all have gamete-producing organs known as
gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are t ...
s. In females, these gonads are then connected by
oviduct The oviduct is the passageway in animals from an ovary The ovary is an organ found in the female reproductive system The female reproductive system is made up of the internal and external sex organs that function in reproduction of new of ...
s to an opening to the outside of the body, typically the cloaca, but sometimes to a unique pore such as a
vagina In mammal Mammals (from Latin language, Latin , 'breast') are a group of vertebrate animals constituting the class (biology), class Mammalia (), and characterized by the presence of mammary glands which in Female#Mammalian female, femal ...

vagina
or
intromittent organ An intromittent organ is a general term for an external organ of a male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete, or ovum, in the process of fertilization. ...
.


Humans

The
human reproductive system The human reproductive system includes the male reproductive system The male reproductive system consists of a number of sex organ A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. ...

human reproductive system
usually involves
internal fertilization Internal fertilization is the union of an egg An egg is the organic vessel containing the in which an develops until it can survive on its own, at which point the animal hatches. An egg results from of an . Most s, (excluding s), and ...
by
sexual intercourse Sexual intercourse (or coitus or copulation) is a sexual activity Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality Human sexuality is the w ...

sexual intercourse
. During this process, the male inserts their
erect penis An erection (clinically: penile erection or penile tumescence) is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, vascular, ...

erect penis
into the
female's
female's
vagina In mammal Mammals (from Latin language, Latin , 'breast') are a group of vertebrate animals constituting the class (biology), class Mammalia (), and characterized by the presence of mammary glands which in Female#Mammalian female, femal ...

vagina
and
ejaculate Ejaculation is the discharge of semen Semen, also known as seminal fluid, is an organic fluid created to contain spermatozoon, spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphrodite, her ...
s
semen Semen, also known as seminal fluid, is an organic fluid created to contain spermatozoon, spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphrodite, hermaphroditic animals and can fertilization, f ...

semen
, which contains
sperm Sperm is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as ...

sperm
. The sperm then travels through the vagina and cervix into the
uterus The uterus (from Latin "uterus", plural ''uteri'') or womb () is the main female hormone-responsive, sex organ, secondary sex organ of the reproductive system in humans and most other mammals. Things occurring in the uterus are described with t ...

uterus
or
fallopian tube The Fallopian tubes, also known as uterine tubes, salpinges (singular salpinx), or oviducts, are tubes that stretch from the ovaries The ovary is an organ found in the female reproductive system 400px, 1. Labia_majora.html"_;"title="V ...

fallopian tube
s for fertilization of the
ovum The egg cell, or ovum (plural ova), is the female reproductive Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduct ...

ovum
. Upon successful
fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise.2C -ize .28-isation.2C -ization.29, spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes ...

fertilization
and implantation,
gestation Gestation is the period of development Development or developing may refer to: Arts *Development hell, when a project is stuck in development *Filmmaking#Development, Filmmaking, development phase, including finance and budgeting *Development ...
of the
fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo An embryo is the early stage of development of a multicellular organism A multicellular organism is an organism tha ...

fetus
then occurs within the female's uterus for approximately nine months, this process is known as
pregnancy Pregnancy, also known as gestation, is the time during which one or more offspring In biology, offspring are the young creation of living organisms, produced either by a Asexual reproduction, single organism or, in the case of sexual repr ...

pregnancy
in humans. Gestation ends with
childbirth Childbirth, also known as labour or delivery, is the ending of pregnancy Pregnancy, also known as gestation, is the time during which one or more offspring In biology, offspring are the young born of living organism, organisms, produc ...

childbirth
, delivery following
labor Labour or labor may refer to: * , the delivery of a baby * , or work ** , physical work ** , a socioeconomic relationship between a worker and an employer Literature * , an American quarterly on the history of the labor movement * ', an academic ...

labor
. Labor consists of the
muscle Skeletal muscles (commonly referred to as muscles) are organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly cat ...

muscle
s of the uterus contracting, the cervix dilating, and the baby passing out the vagina (the female genital organ). Human's babies and children are nearly helpless and require high levels of
parental care Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) ...

parental care
for many years. One important type of parental care is the use of the
mammary gland A mammary gland is an exocrine gland Exocrine glands are gland In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormone A hormone (from the Greek participle , "setting in motion") is any m ...
s in the female
breast The breast is one of two prominences located on the upper ventral Standard anatomical terms of location deal unambiguously with the of s, including s. Terms used generally derive from or roots and used to describe something in its . Th ...

breast
s to
nurse Nursing is a profession within the health care Healthcare is the maintenance or improvement of health Health is a state of physical, mental and social well-being Well-being, also known as ''wellness'', ''prudential value'' or ''qua ...

nurse
the baby. The female reproductive system has two functions: The first is to produce egg cells, and the second is to protect and nourish the offspring until birth. The male reproductive system has one function, and it is to produce and deposit sperm. Humans have a high level of
sexual differentiation Sexual differentiation is the process of development of the sex Sex is either of two divisions, typically male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete ...
. In addition to differences in nearly every reproductive organ, numerous differences typically occur in
secondary sexual characteristic Secondary sex characteristics are features that appear during puberty in human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedality, bipedalism and large, complex brains. This has ena ...
s.


=Male

= The
male reproductive system The male reproductive system consists of a number of sex organ A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. ...

male reproductive system
is a series of organs located outside of the body and around the pelvic region of a
male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot sexual reproduction, reproduce sexually ...

male
that contribute towards the reproduction process. The primary direct function of the male reproductive system is to provide the male sperm for fertilization of the ovum. The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the
testes Testicle or testis (plural testes) is the male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male or ...

testes
which are housed in the temperature regulating
scrotum The scrotum or scrotal sac is an Anatomy, anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scr ...

scrotum
, immature sperm then travel to the
epididymis The epididymis (; plural: epididymides or ) is a tube that connects a testicle Testicle or testis (plural testes) is the male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses w ...

epididymis
for development and storage. The second category is the ejaculatory fluid-producing glands which include the
seminal vesicles The seminal vesicles (also called vesicular glands, or seminal glands), are a pair of two convoluted tubular glands that lie behind the urinary bladder The urinary bladder, or simply bladder, is a hollow muscular organ in humans and other ver ...

seminal vesicles
,
prostate The prostate is both an accessory gland of the male reproductive system The male reproductive system consists of a number of sex organ A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual repr ...

prostate
, and the
vas deferens The vas deferens, or ductus deferens, is part of the male reproductive system The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the ...

vas deferens
. The final category are those used for copulation, and deposition of the
spermatozoa A spermatozoon (pronounced , alternate spelling spermatozoön; plural spermatozoa; from grc, σπέρμα ("seed") and grc, ζῷον ("living being")) is a motile Motility is the ability of an organism In biology, an organism () ...

spermatozoa
(
sperm Sperm is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as ...

sperm
) within the male, these include the
penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during Copulation (zoology), copulation. Such organs occur in many animals, both #Vertebrates, vertebrate ...

penis
,
urethra The urethra (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is appro ...

urethra
,
vas deferens The vas deferens, or ductus deferens, is part of the male reproductive system The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the ...

vas deferens
, and
Cowper's gland The bulbourethral gland or Cowper's gland (named for English anatomist William Cowper William Cowper ( ; 26 November 1731 – 25 April 1800) was an English poet and hymnodist. One of the most popular poets of his time, Cowper changed t ...
. Major secondary sex characteristics include larger, more muscular stature, deepened voice,
facial A facial is a family of skin care treatments for the face The face is the front of an animal's head that features the eyes Eyes are organs An organ is a group of tissues with similar functions. Plant life and animal life rely on ma ...
and
body hair Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic ...
, broad shoulders, and development of an
Adam's apple The Adam's apple or laryngeal prominence, is the lump or protrusion in the human neck The neck is the part of the body on many vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular ...
. An important sexual hormone of males is
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone A steroid hormone is a steroid , hypothetical a steroid with 32 carbon atoms. Its core ring system (ABCD), composed of 17 c ...
, and particularly
testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testes and prostate, as well as promoting secondar ...
. The testes release a hormone that controls the development of sperm. This hormone is also responsible for the development of physical characteristics in men such as facial hair and a deep voice.


=Female

= The human female reproductive system is a series of organs primarily located inside of the body and around the
pelvic The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen The abdomen (colloquially called the belly, tummy, midriff or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in o ...

pelvic
region of a
female Female (symbol: ♀) is the sex Sex is either of two divisions, typically male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete, or ovum, in the process of ...

female
that contribute towards the
reproductive Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual orga ...

reproductive
process. The human female reproductive system contains three main parts: the
vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis In human anatomy The human body is the structure of a human being. It is com ...

vulva
, which leads to the vagina, the vaginal opening, to the uterus; the
uterus The uterus (from Latin "uterus", plural ''uteri'') or womb () is the main female hormone-responsive, sex organ, secondary sex organ of the reproductive system in humans and most other mammals. Things occurring in the uterus are described with t ...

uterus
, which holds the developing fetus; and the
ovaries The ovary is an organ found in the female reproductive system 300px, 1. Labia_majora.html"_;"title="Vulva: 2. Labia_majora">Vulva: 2. Labia_majora; 3. Labia_minora; 4. Vulval_vestibule.html" "title="Labia_minora.html ...

ovaries
, which produce the female's ova. The
breast The breast is one of two prominences located on the upper ventral Standard anatomical terms of location deal unambiguously with the of s, including s. Terms used generally derive from or roots and used to describe something in its . Th ...

breast
s are involved during the parenting stage of reproduction, but in most classifications they are not considered to be part of the female reproductive system. The vagina meets the outside at the
vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis In human anatomy The human body is the structure of a human being. It is com ...

vulva
, which also includes the
labia The labia are part of the female genitalia; they are the major externally visible portions of the vulva. In humans, there are two pairs of labia: the ''labia majora'' (or the outer labia) are larger and thicker, while the ''labia minora'' are fold ...
,
clitoris The clitoris ( or ) is a female sex organ present in mammals, ostriches and a limited number of #Other animals, other animals. In humans, the visible portion – the glans – is at the front junction of the labia minora (inner lips), ...

clitoris
and
urethra The urethra (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is appro ...

urethra
; during intercourse this area is lubricated by mucus secreted by the Bartholin's glands. The vagina is attached to the uterus through the
cervix The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus The uterus (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. L ...

cervix
, while the uterus is attached to the ovaries via the
fallopian tubes The Fallopian tubes, also known as uterine tubes, salpinges (singular salpinx), or oviducts, are tubes that stretch from the to the , in the human . In other mammals they are called s. A passes through the Fallopian tubes from the ovaries t ...
. Each ovary contains hundreds of ova (singular ''
ovum The egg cell, or ovum (plural ova), is the female reproductive Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduct ...

ovum
''). Approximately
every 28 days
every 28 days
, the
pituitary gland upright=1.2, The Hypothalamus-Pituitary Complex. In vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingd ...

pituitary gland
releases a
hormone A hormone (from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is appr ...

hormone
that stimulates some of the ova to develop and grow. One ovum is released and it passes through the fallopian tube into the uterus. Hormones produced by the ovaries prepare the uterus to receive the ovum. The ovum will move through her
fallopian tubes The Fallopian tubes, also known as uterine tubes, salpinges (singular salpinx), or oviducts, are tubes that stretch from the to the , in the human . In other mammals they are called s. A passes through the Fallopian tubes from the ovaries t ...
and awaits the sperm for fertilization to occur. When this does not occur i.e. no sperm for fertilization, the lining of the uterus, called the
endometrium The endometrium is the inner epithelial Epithelium is one of the four basic types of animal Tissue (biology), tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly pac ...

endometrium
, and unfertilized ova are shed each cycle through the process of
menstruation Menstruation (also known as a period and many other Colloquialism, colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycl ...
. If the ovum is fertilized by sperm, it will attach to the endometrium and embryonic development will begin.


Other mammals

Most
mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be i ...
reproductive systems are similar, however, there are some notable differences between the non-human mammals and humans. For instance, most male mammals have
a penis
a penis
which is stored internally until erect, and most have a penis bone or
baculum The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of the skeleton in most vertebrate animals. Bones protect the ...
. Additionally, males of most species do not remain continually sexually fertile as humans do. Like humans, most groups of mammals have descended testicles found within a scrotum, however, others have descended testicles that rest on the ventral body wall, and a few groups of mammals, such as elephants, have undescended testicles found deep within their body cavities near their
kidney The kidneys are two reddish-brown bean-shaped organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized ...

kidney
s. The reproductive system of marsupials is unique in that the female has two vaginae, both of which open externally through one orifice but lead to different compartments within the uterus; males usually have a two-pronged penis, which corresponds to the females' two vaginae. Marsupials typically develop their offspring in an external pouch containing
teat A teat is the projection from the mammary gland A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands a ...
s to which their newborn young (
joey Joey may refer to: People *Joey (name) Joey is an English language, English-language given name used for both males and females. It can be a short form of: * Joseph, for males * Joel (given name), Joel, for males * Josiah (given name), Josiah, ...
s) attach themselves for post uterine development. Also, marsupials have a unique prepenial scrotum. The long newborn joey instinctively crawls and wriggles the , while clinging to fur, on the way to its mother's pouch. The uterus and vagina are unique to mammals with no homologue in birds, reptiles, amphibians, or fish. In place of the uterus the other
vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic ma ...
groups have an unmodified oviduct leading directly to a
cloaca In animal anatomy, a cloaca (plural cloacae or ) is the posterior that serves as the only opening for the , reproductive, and s (if present) of many animals. All s, s, birds, and a few mammals (s, s, s, and s) have this orifice, from which ...
, which is a shared exit-hole for gametes,
urine Urine is a liquid by-product A by-product or byproduct is a secondary product derived from a production process, process or ; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be cons ...

urine
, and
feces Feces ( or faeces) is the solid or semi-solid remains of food that was not digested in the small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where mos ...

feces
. Monotremes (i.e.
platypus The platypus (''Ornithorhynchus anatinus''), sometimes referred to as the duck-billed platypus, is a List of semiaquatic tetrapods, semiaquatic, egg-laying mammal Endemic (ecology), endemic to Eastern states of Australia, eastern Australia, ...

platypus
and
echidna Echidnas (), sometimes known as spiny anteaters, are quill-covered monotremes Monotremes are one of the three main groups of living mammal Mammals (from Latin language, Latin , 'breast') are a group of vertebrate animals constituti ...

echidna
s), a group of egg-laying mammals, also lack a uterus and vagina, and in that respect have a reproductive system resembling that of a reptile.


=Dogs

= In domestic canines, sexual maturity (puberty) occurs between the ages of 6 to 12 months for both males and females, although this can be delayed until up to two years of age for some large breeds.


=Horses

= The mare's reproductive system is responsible for controlling gestation, birth, and lactation, as well as her estrous cycle and mating behavior. The stallion's reproductive system is responsible for his sexual behavior and secondary sex characteristics (such as a large crest).


Birds

Male and female birds have a
cloaca In animal anatomy, a cloaca (plural cloacae or ) is the posterior that serves as the only opening for the , reproductive, and s (if present) of many animals. All s, s, birds, and a few mammals (s, s, s, and s) have this orifice, from which ...
, an opening through which eggs, sperm, and wastes pass. Intercourse is performed by pressing the lips of the cloacae together, which is sometimes known as
intromittent organ An intromittent organ is a general term for an external organ of a male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete, or ovum, in the process of fertilization. ...
which is known as a phallus that is
analogous Analogy (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approximate ...
to the
mammals' penis
mammals' penis
. The female lays amniotic eggs in which the young fetus continues to develop after it leaves the female's body. Unlike most vertebrates female birds typically have only one functional ovary and
oviduct The oviduct is the passageway in animals from an ovary The ovary is an organ found in the female reproductive system The female reproductive system is made up of the internal and external sex organs that function in reproduction of new of ...
. As a group, birds, like mammals, are noted for their high level of parental care.


Reptiles

Reptiles Reptiles, as most commonly defined, are the animals in the class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or ...

Reptiles
are almost all
sexually dimorphic Sexual dimorphism is the condition where the sexes of the same species exhibit different characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may in ...
, and exhibit internal fertilization through the cloaca. Some reptiles lay
egg An egg is the organic vessel containing the in which an develops until it can survive on its own, at which point the animal hatches. An egg results from of an . Most s, (excluding s), and lay eggs, although some, such as s, do not. eg ...
s while others are ovoviviparous (animals that deliver live young). Reproductive organs are found within the cloaca of reptiles. Most male reptiles have copulatory organs, which are usually retracted or inverted and stored inside the body. In turtles and crocodilians, the male has a single median penis-like organ, while male snakes and lizards each possess a pair of penis-like organs.


Amphibians

Most
amphibian Amphibians are ectothermic, tetrapod vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial animal, ter ...
s exhibit external fertilization of eggs, typically within the water, though some amphibians such as
caecilian Caecilians (; New Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was origina ...

caecilian
s have internal fertilization. All have paired, internal gonads, connected by ducts to the cloaca.


Fish

Fish Fish are aquatic Aquatic means relating to water Water (chemical formula H2O) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the ...

Fish
exhibit a wide range of different reproductive strategies. Most fish, however, are
oviparous Oviparous animals are female animals that lay their egg Diagram of a chicken egg in its 9th day. Membranes: allantois, chorion, amnion, and vitellus/ yolk. An egg is the organic vessel containing the zygote in which an embryo develops un ...
and exhibit external fertilization. In this process, females use their cloaca to release large quantities of their gametes, called
spawn Spawn or spawning may refer to: * Spawn (biology) Spawn is the eggs Eggs are laid by female animals of many different species, including bird egg, birds, reptiles, amphibians, a few monotreme, mammals, and fish, and many of these have bee ...
into the water and one or more males release "milt", a white fluid containing many sperm over the unfertilized eggs. Other species of fish are oviparous and have internal fertilization aided by pelvic or anal
fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust Thrust is a reaction (physics), reaction force (physics), force described quantitatively by Newton' ...

fin
s that are modified into an
intromittent organ An intromittent organ is a general term for an external organ of a male Male (♂) is the sex of an organism that produces the gamete known as sperm. A male gamete can fuse with a larger female gamete, or ovum, in the process of fertilization. ...
analogous to the human penis. A small portion of fish species are either viviparous or
ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is an outmoded term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals have the embryos develop ...
, and are collectively known as
livebearer Guppy fry Livebearers are aquarium fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. They form a sister group to the tunicates, together forming the Chordate#T ...
s. Fish gonads are typically pairs of either ovaries or testes. Most fish are sexually dimorphic but some species are
hermaphroditic In reproductive biology, a hermaphrodite () is an organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology, properties of life ...

hermaphroditic
or
unisexual In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanisms, ...
.


Invertebrates

Invertebrate Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This includes all animals apart from the chordata, chordate subphylum vertebrate, Vertebra ...
s have an extremely diverse array of reproductive systems, the only commonality may be that they all lay eggs. Also, aside from
cephalopod A cephalopod is any member of the mollusca Mollusca is the second-largest phylum In biology, a phylum (; plural The plural (sometimes list of glossing abbreviations, abbreviated ), in many languages, is one of the values of the gram ...
s and
arthropod An arthropod (, (gen. ποδός)) is an invertebrate animal having an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Euarthropoda,Reference showing that Euarthropoda is a phylum: ...
s, nearly all other invertebrates are
hermaphroditic In reproductive biology, a hermaphrodite () is an organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology, properties of life ...
and exhibit
external fertilization External fertilization is a mode of reproduction Reproduction (or procreation or breeding) is the biological process Biological processes are those processes that are vital for an organism In biology, an organism (from Ancient Greek ...
.


Cephalopods

All
cephalopod A cephalopod is any member of the mollusca Mollusca is the second-largest phylum In biology, a phylum (; plural The plural (sometimes list of glossing abbreviations, abbreviated ), in many languages, is one of the values of the gram ...
s are
sexually dimorphic Sexual dimorphism is the condition where the sexes of the same species exhibit different characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may in ...
and reproduce by laying
egg An egg is the organic vessel containing the in which an develops until it can survive on its own, at which point the animal hatches. An egg results from of an . Most s, (excluding s), and lay eggs, although some, such as s, do not. eg ...
s. Most cephalopods have semi-internal fertilization, in which the male places his gametes inside the female's mantle cavity or pallial cavity to fertilize the
ova , abbreviated as OVA and sometimes as OAV (original animation video), are Japanese animated films and series made specially for release in home video Home video is prerecorded media sold or Video rental shop, rented for home viewing. The ter ...

ova
found in the female's single
ovary The ovary is an organ found in the female reproductive system The female reproductive system is made up of the internal and external sex organs that function in reproduction of new offspring. In humans, the female reproductive system is im ...

ovary
. Likewise, male cephalopods have only a single
testicle Testicle or testis (plural testes) is the male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male or ...

testicle
. In the female of most cephalopods the
nidamental gland 250px, Ventral view of the viscera of '' Chtenopteryx sicula'', showing the presence of the nidamental glands and accessory nidamental glands. Nidamental glands are internal organ An organ is a group of tissues with similar functions. Plant lif ...
s aid in development of the egg. The "penis" in most unshelled male cephalopods (
Coleoidea Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopod A cephalopod is any member of the mollusca Mollusca is the second-largest phylum In biology, a phylum (; plural The plural (sometimes list of glossing abbreviati ...
) is a long and muscular end of the gonoduct used to transfer spermatophores to a modified arm called a
hectocotylus A hectocotylus (plural: ''hectocotyli'') is one of the arm In human anatomy, the arm is the part of the upper limb The upper Limb (anatomy), limbs or upper extremities are the forelimbs of an upright posture, upright-postured tetrapod vertebrat ...
. That in turn is used to transfer the spermatophores to the female. In species where the hectocotylus is missing, the "penis" is long and able to extend beyond the mantle cavity and transfer the spermatophores directly to the female.


Insects

Most
insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be in ...

insect
s reproduce
oviparous Oviparous animals are female animals that lay their egg Diagram of a chicken egg in its 9th day. Membranes: allantois, chorion, amnion, and vitellus/ yolk. An egg is the organic vessel containing the zygote in which an embryo develops un ...
ly, i.e. by laying
egg An egg is the organic vessel containing the in which an develops until it can survive on its own, at which point the animal hatches. An egg results from of an . Most s, (excluding s), and lay eggs, although some, such as s, do not. eg ...

egg
s. The eggs are produced by the female in a pair of
ovaries The ovary is an organ found in the female reproductive system 300px, 1. Labia_majora.html"_;"title="Vulva: 2. Labia_majora">Vulva: 2. Labia_majora; 3. Labia_minora; 4. Vulval_vestibule.html" "title="Labia_minora.html ...

ovaries
.
Sperm Sperm is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as ...

Sperm
, produced by the male in one
testis Testicle or testis (plural testes) is the male reproductive gland or gonad in all animals, including humans. It is Homology (biology), homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primari ...

testis
or more commonly two, is transmitted to the female during
mating In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanis ...

mating
by means of external
genitalia A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, ar ...

genitalia
. The sperm is stored within the female in one or more
spermatheca The spermatheca (pronounced plural: spermathecae ), also called receptaculum seminis (plural: receptacula seminis), is an organ Organ may refer to: Biology * Organ (anatomy) An organ is a group of Tissue (biology), tissues with similar f ...
e. At the time of
fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise.2C -ize .28-isation.2C -ization.29, spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes ...

fertilization
, the eggs travel along
oviduct The oviduct is the passageway in animals from an ovary The ovary is an organ found in the female reproductive system The female reproductive system is made up of the internal and external sex organs that function in reproduction of new of ...
s to be fertilized by the sperm and are then expelled from the body ("laid"), in most cases via an
ovipositor The ovipositor is a tube-like organ (anatomy), organ used by some animals, especially insects, for the laying of Egg (biology), eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of t ...
.


Arachnids

Arachnids may have one or two
gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are t ...
s, which are located in the abdomen. The genital opening is usually located on the underside of the second abdominal segment. In most species, the male transfers sperm to the female in a package, or
spermatophore A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa A spermatozoon (pronounced , alternate spelling spermatozoön; plural spermatozoa; from grc, σπέρμα ("seed") and grc, ζῷον ("living being")) is a motile spe ...
. Complex courtship rituals have evolved in many arachnids to ensure the safe delivery of the sperm to the female. Arachnids usually lay yolky
eggs Egg An egg is the organic vessel containing the in which an develops until it can survive on its own, at which point the animal hatches. An egg results from of an . Most s, (excluding s), and lay eggs, although some, such as s, do ...
, which hatch into immatures that resemble adults. Scorpions, however, are either
ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is an outmoded term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals have the embryos develop ...
or
viviparous Among animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aero ...
, depending on species, and bear live young.


Plants

Among all living organisms,
flower A flower, sometimes known as a bloom or blossom Image:Cerisier du Japon Prunus serrulata.jpg, Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tree, trees (genus ''Prunus'') and of some other plan ...

flower
s, which are the reproductive structures of
angiosperms Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greec ...

angiosperms
, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants ( green algae,
moss Mosses are small, non-vascular flower A flower, sometimes known as a bloom or blossom Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tree, trees (genus ''Prunus'') and of some other plant ...

moss
es,
liverwort The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte A gametophyte () is one of the two alternation of generations, alternating m ...
s,
hornwort Hornworts are a group of bryophyte Bryophytes are an informal group consisting of three divisions Division or divider may refer to: Mathematics *Division (mathematics) Division is one of the four basic operations of arithmetic, the ways th ...
s,
fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia art ...

fern
s and
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also ...
s such as
conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single e ...
s) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations.
Christian Konrad Sprengel Christian Konrad Sprengel (22 September 1750 – 7 April 1816) was a German naturalist Natural history is a domain of inquiry involving organisms, including animals, fungus, fungi, and plants, in their natural environment, leaning more ...
(1793) studied the reproduction of flowering plants and for the first time it was understood that the
pollination Pollination is the transfer of pollen Pollen is a powdery substance consisting of pollen grains which are Sporophyte, microsporophytes of spermatophyta, seed plants, which produce male gametes (sperm cells). Pollen grains have a hard coat ...

pollination
process involved both
biotic Biotics describe living or once living components of a community; for example organisms, such as animals and plants. Biotic may refer to: *Life, the condition of living organisms *Biology, the study of life *Biotic material, which is derived from l ...
and
abiotic
abiotic
interactions.


Fungi

Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the
life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring *Life-cycle hypothesis, ...
of a species, the
teleomorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the Biological life cycle, life cycles of fungi in the Phylum, phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a Ascoc ...
and the
anamorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the Biological life cycle, life cycles of fungi in the Phylum, phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a Asco ...

anamorph
.Kirk ''et al''., p. 633. Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing
propagule In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanisms, ...
s.


See also

*
Major systems of the human body
Major systems of the human body
* Reproductive system disease *
Human sexuality Human sexuality is the way people experience and express themselves sexually. This involves biological Biology is the natural science Natural science is a branch of science Science (from the Latin word ''scientia'', meaning ...
*
Human sexual behavior Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their Human sexuality, sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g. ...
*
Plant sexuality Plant reproductive morphology is the study of the physical form and structure (the morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifac ...
*
Meiosis Meiosis (; , because it is a reductional division) is a special type of of in organisms used to produce the , such as or . It involves two rounds of division that ultimately result in four cells with only one copy of each (). Additionall ...

Meiosis


References


Cited literature

* *


External links

{{Authority control Fertility Endocrine system