Sex organ

The sex organs of a green algae Chara are the male antheridia (red) and female archegonia (brown).
The female genitalia of Lepidoptera

Any part of an animal or plant that is involved in sexual reproduction.

- Sex organ
The sex organs of a green algae Chara are the male antheridia (red) and female archegonia (brown).

18 related topics

Alpha

A pair of ovaries of Cyprinus carpio (common carp) placed in dissecting dish

Gonad

Mixed gland that produces the gametes and sex hormones of an organism.

Mixed gland that produces the gametes and sex hormones of an organism.

A pair of ovaries of Cyprinus carpio (common carp) placed in dissecting dish

Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of gonadal ridges, and only later are differentiated to male or female sex organs.

Stamens of a Hippeastrum with white filaments and prominent anthers carrying pollen

Stamen

Stamens of a Hippeastrum with white filaments and prominent anthers carrying pollen
Hippeastrum flowers showing stamens above the style (with its terminal stigma)
Closeup of stamens and stigma of Lilium 'Stargazer'
Stamens, with distal anther attached to the filament stalk, in context of floral anatomy
Cross section of a Lilium stamen, with four locules surrounded by the tapetum
Stamen with pollinia and its anther cap. Phalaenopsis orchid.

The stamen (plural stamina or stamens) is the pollen-producing reproductive organ of a flower.

Diagram of the scrotum. On the left side the cavity of the tunica vaginalis has been opened; on the right side only the layers superficial to the Cremaster muscle have been removed.

Scrotum

Anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle.

Anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle.

Diagram of the scrotum. On the left side the cavity of the tunica vaginalis has been opened; on the right side only the layers superficial to the Cremaster muscle have been removed.
Image showing musculature and inner workings of the scrotum.
Stages in the development of the male external genitalia.
Human scrotum in a relaxed state (left) and a tense state (right)

Male sex hormones are secreted by the testes later in embryonic life to cause the development of secondary sex organs.

Section of the fold in the mesonephros of a chick embryo of the fourth day.

Development of the reproductive system

Section of the fold in the mesonephros of a chick embryo of the fourth day.
Tail end of human embryo thirty-two to thirty-three days old. The endodermal cloaca is visible at center left, labeled in green
Development of external genitalia. A: common development. C, E: male development. B, D, F: female development
Diagrams to show the development of male and female generative organs from a common type.

The development of the reproductive system is the part of embryonic growth that results in the sex organs and contributes to sexual differentiation.

In the first stage of sexual reproduction, "meiosis", the number of chromosomes is reduced from a diploid number (2n) to a haploid number (n). During "fertilisation", haploid gametes come together to form a diploid zygote, and the original number of chromosomes is restored.

Sexual reproduction

Type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes (haploid) combines with another to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid).

Type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes (haploid) combines with another to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid).

In the first stage of sexual reproduction, "meiosis", the number of chromosomes is reduced from a diploid number (2n) to a haploid number (n). During "fertilisation", haploid gametes come together to form a diploid zygote, and the original number of chromosomes is restored.
An Australian emperor dragonfly laying eggs, guarded by a male
Flowers contain the sexual organs of flowering plants.
Puffballs emitting spores

Dimorphism is found in both sex organs and in secondary sex characteristics, body size, physical strength and morphology, biological ornamentation, behavior and other bodily traits.

The principle of homology: The biological relationships (shown by colours) of the bones in the forelimbs of vertebrates were used by Charles Darwin as an argument in favor of evolution.

Homology (biology)

Similarity due to shared ancestry between a pair of structures or genes in different taxa.

Similarity due to shared ancestry between a pair of structures or genes in different taxa.

The principle of homology: The biological relationships (shown by colours) of the bones in the forelimbs of vertebrates were used by Charles Darwin as an argument in favor of evolution.
Pierre Belon systematically compared the skeletons of birds and humans in his Book of Birds (1555).
Sycamore maple fruits have wings analogous but not homologous to an insect's wings.
pax6 alterations result in similar changes to eye morphology and function across a wide range of taxa.
Hox genes in arthropod segmentation
The ABC model of flower development. Class A genes affect sepals and petals, class B genes affect petals and stamens, class C genes affect stamens and carpels. In two specific whorls of the floral meristem, each class of organ identity genes is switched on.
The Cretaceous snake Pachyrhachis problematicus had hind legs (circled).
A multiple sequence alignment of mammalian histone H1 proteins. Alignment positions conserved across all five species analysed are highlighted in grey. Positions with conservative, semi-conservative, and non-conservative amino acid replacements are indicated.
Dominance hierarchy behaviour, as in these weeper capuchin monkeys, may be homologous across the primates.
One pinnate leaf of European ash
Detail of palm leaf
Leaf petioles adapted as spines in Fouquieria splendens
The very large leaves of the banana, Musa acuminata
Succulent water storage leaf of Aloe
Insect-trapping leaf of Venus flytrap
Insect-trapping leaf of pitcher plant
Food storage leaves in an onion bulb
The Cretaceous snake Pachyrhachis problematicus had hind legs (circled).

Male and female reproductive organs are homologous if they develop from the same embryonic tissue, as do the ovaries and testicles of mammals including humans.

Embryophyte

The Embryophyta, or land plants, are the most familiar group of green plants that comprise vegetation on Earth.

The Embryophyta, or land plants, are the most familiar group of green plants that comprise vegetation on Earth.

Moss, clubmoss, ferns and cycads in a greenhouse
Most bryophytes, such as these mosses, produce stalked sporophytes from which their spores are released.
Reconstruction of a plant of Rhynia
Lycopodiella inundata, a lycophyte
Athyrium filix-femina, unrolling young frond
Pine forest in France
Large seed of a horse chestnut, Aesculus hippocastanum

Embryophytes are complex multicellular eukaryotes with specialized reproductive organs.

The ventral side (underside) of a female American lobster, a member of the class Malacostraca. The gonopores are at the bases of the third walking leg, pointing towards the animal's tail.

Gonopore

The ventral side (underside) of a female American lobster, a member of the class Malacostraca. The gonopores are at the bases of the third walking leg, pointing towards the animal's tail.

A gonopore, sometimes called a gonadopore, is a genital pore in many invertebrates.