Changes

== Introduction ==

== Introduction ==

* Both male and female must be present.

* Both male and female must be present.

* Both sperm and [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]] contribute to the embryo.

* Both sperm and [[Oogenesis - Anatomy & Physiology|oocyte]] contribute to the embryo.

== Gynogenesis ==

== Gynogenesis ==

* 99% female contribution.

* 99% female contribution.

* Mitosis occurs without separation and meiosis follows.

* Mitosis occurs without separation and meiosis follows.

* Sperm nucleus does not enter the [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]] to form the diploid state.

* Sperm nucleus does not enter the [[Oogenesis - Anatomy & Physiology|oocyte]] to form the diploid state.

** Sperm contributes no genetic material to the embryo.

** Sperm contributes no genetic material to the embryo.

* Sperm are only required to [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Fertilisation-_Anatomy_%26_Physiology#Syngamy|activate]] the embryo.

* Sperm are only required to [[Fertilisation - Anatomy & Physiology#Syngamy|activate]] the embryo.

== Parthenogenesis ==

== Parthenogenesis ==

* An asexual form of reproduction found in females where growth and development of embryos  occurs without fertilization by males.  

* An asexual form of reproduction found in females where growth and development of embryos  occurs without fertilization by males.  

* 100% female contribution.

* 100% female contribution.

* Self-activated [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocytes]] require no contribution from sperm.

* Self-activated [[Oogenesis - Anatomy & Physiology|oocytes]] require no contribution from sperm.

* The offspring produced by parthenogenesis almost always are female in species where the XY chromosome system determines gender.

* The offspring produced by parthenogenesis almost always are female in species where the XY chromosome system determines gender.

=== Ovaries ===

=== Ovaries ===

* Produce 1-25,000 [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocytes]] at a time.

* Produce 1-25,000 [[Oogenesis - Anatomy & Physiology|oocytes]] at a time.

* Under the influence of the [[Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]].

* Under the influence of the [[Pituitary_Gland_- Anatomy & Physiology|pituitary gland]].

* [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|Oocytes]] squeeze out into the [[Peritoneal_cavity_-_Anatomy_%26_Physiology|peritoneal cavity (ceolom)]].

* [[Oogenesis - Anatomy & Physiology|Oocytes]] squeeze out into the [[Peritoneal_Cavity_- Anatomy & Physiology|peritoneal cavity (ceolom)]].

* Cilia in the ceolom direct the ova into the infundibulum of the oviduct.

* Cilia in the ceolom direct the ova into the infundibulum of the oviduct.

* The oviduct (Mullarian Duct) covers the egg with a jelly-like material.

* The oviduct (Mullarian Duct) covers the egg with a jelly-like material.

* Oviduct and utreter may be united through much of their length.

* Oviduct and utreter may be united through much of their length.

* Open into the [[Exotics_-_Amphibian_Reproductive_Anatomy_and_Physiology_-_Anatomy_%26_Physiology#Cloaca|cloaca]].

* Open into the cloaca.

=== Testes ===

=== Testes ===

* Located near the [[Urinary System - Anatomy & Physiology|kidneys]].

* Located near the [[Urinary System Overview - Anatomy & Physiology|kidneys]].

* Produce sperm under the influence of the [[Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]].

* Produce sperm under the influence of the [[Pituitary_Gland_- Anatomy & Physiology|pituitary gland]].

* Often a rudimentary [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|ovary]] (known as the Bidder's organ)nearby in the male.

* Often a rudimentary [[Ovary - Anatomy & Physiology|ovary]] (known as the Bidder's organ)nearby in the male.

==== Bidder's Organ ====

==== Bidder's Organ ====

* Bidder's organ is a spherical, brownish organ in toads.

* Bidder's organ is a spherical, brownish organ in toads.

* The organ is located just in front of the [[Urinary System - Anatomy & Physiology|kidney]] (mesonephros).

* The organ is located just in front of the [[Urinary System Overview - Anatomy & Physiology|kidney]] (mesonephros).

* It is formed at the cranial tip of the male and female gonad during the larval stage.  

* It is formed at the cranial tip of the male and female gonad during the larval stage.  

* Normally it is inactive and contains miniature [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicles]] which have the capability to mature (becoming active).

* Normally it is inactive and contains miniature [[Follicles - Anatomy & Physiology|follicles]] which have the capability to mature (becoming active).

* When the female population is scarce, the Bidder's organ enlarges and produces viable oocytes and then gonadotropins, which stimulate the growth of the Müllerian ducts to form uterus and oviducts.

* When the female population is scarce, the Bidder's organ enlarges and produces viable oocytes and then gonadotropins, which stimulate the growth of the Müllerian ducts to form uterus and oviducts.

* Its internal anatomy consists of two parts:

* Its internal anatomy consists of two parts:

** Central portion: consists of connective tissue and rich in blood vessels.

** Central portion: consists of connective tissue and rich in blood vessels.

** Periphery: consists of the cortex, which contains [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicles]] in various stages of development.  

** Periphery: consists of the cortex, which contains [[Follicles - Anatomy & Physiology|follicles]] in various stages of development.  

** Molecules of various proteins are present in the outer layer of the [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicles]], homologous to the zona pellucida of the ovum.

** Molecules of various proteins are present in the outer layer of the [[Follicles - Anatomy & Physiology|follicles]], homologous to the zona pellucida of the ovum.

=== Male Ducts ===

=== Male Ducts ===

* 75% of the species are viviparous, meaning that they give birth to already developed offspring. The fetus is fed inside the female with special cells of the oviduct, which are eaten by the fetus with special scraping teeth.

* 75% of the species are viviparous, meaning that they give birth to already developed offspring. The fetus is fed inside the female with special cells of the oviduct, which are eaten by the fetus with special scraping teeth.

** The egg laying species Boulengerula taitanus feeds its young by developing a special outer layer of skin, high in fat and other nutrients, which the young peel off with similar teeth. This allows them to grow by up to ten times their own weight in a week. The skin is consumed every three days, the time it takes for a new layer to grow, and the young have only been observed to eat it at night.

** The egg laying species Boulengerula taitanus feeds its young by developing a special outer layer of skin, high in fat and other nutrients, which the young peel off with similar teeth. This allows them to grow by up to ten times their own weight in a week. The skin is consumed every three days, the time it takes for a new layer to grow, and the young have only been observed to eat it at night.