All Topics  
Isogamy

 

 
   Email Print
   Bookmark   Link
 

 

Isogamy
 
 
  Topics Isogamy Topic Home

Isogamy refers to a form of sexual reproduction
Sexual reproduction

Sexual reproduction is characterized by processes that pass a Genetic recombination of Genetics material to offspring, resulting in Genetic diversity....
 involving gamete
Gamete

A gamete is a Cell that fuses with another gamete during fertilization in organisms that sexual reproduction. In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete?called an ovum ?and a male produces th...
s of similar morphology, differing only in allele expression in one or more mating-type regions
Mating-type region

The mating-type region is a specialized region in the genomes of some yeast and other fungi, usually organized into heterochromatin and possessing unique histone methylation patterns....
. Since both gametes look alike, they cannot be classified as "male
Malé

Mal? , population 104,403 , is the Capital , the largest city in terms of population, and the name of an island in the Maldives. It is located at the southern edge of North Male' Atoll Kaafu Atoll....
" or "female
Female

Female is the sex of an organism, or a part of an organism, which produces mobile ovum . The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male....
." Instead, organisms undergoing isogamy are said to have different mating type
Mating type

Mating types occur in eukaryotes that undergo sexual reproduction via isogamy. Since the gametes of different mating types look alike, they are often referred to by numbers, letters, or simply "+" and "-" instead of "male" and "female." Mating can only take place between different mating types....
s, most commonly noted as "+" and "-" strains. Fertilization occurs when "+" and "-" gametes fuse to form a zygote
Zygote

A zygote is a cell that is the result of fertilization. That is, two ploidy cells—usually an ovum from a female and a sperm cell from a male—merge into a single ploidy cell called the zygote ....
.

There are several types of isogamy.






Discussion
Ask a question about 'Isogamy'
Start a new discussion about 'Isogamy'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Isogamy refers to a form of sexual reproduction
Sexual reproduction

Sexual reproduction is characterized by processes that pass a Genetic recombination of Genetics material to offspring, resulting in Genetic diversity....
 involving gamete
Gamete

A gamete is a Cell that fuses with another gamete during fertilization in organisms that sexual reproduction. In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete?called an ovum ?and a male produces th...
s of similar morphology, differing only in allele expression in one or more mating-type regions
Mating-type region

The mating-type region is a specialized region in the genomes of some yeast and other fungi, usually organized into heterochromatin and possessing unique histone methylation patterns....
. Since both gametes look alike, they cannot be classified as "male
Malé

Mal? , population 104,403 , is the Capital , the largest city in terms of population, and the name of an island in the Maldives. It is located at the southern edge of North Male' Atoll Kaafu Atoll....
" or "female
Female

Female is the sex of an organism, or a part of an organism, which produces mobile ovum . The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male....
." Instead, organisms undergoing isogamy are said to have different mating type
Mating type

Mating types occur in eukaryotes that undergo sexual reproduction via isogamy. Since the gametes of different mating types look alike, they are often referred to by numbers, letters, or simply "+" and "-" instead of "male" and "female." Mating can only take place between different mating types....
s, most commonly noted as "+" and "-" strains. Fertilization occurs when "+" and "-" gametes fuse to form a zygote
Zygote

A zygote is a cell that is the result of fertilization. That is, two ploidy cells—usually an ovum from a female and a sperm cell from a male—merge into a single ploidy cell called the zygote ....
.

There are several types of isogamy. Both gametes may be flagellated
Flagellum

A flagellum is a tail-like structure that projects from the cell body of certain prokaryotic and eukaryotic cells, and it functions in locomotion....
 and thus motile. This type occurs for example in algae
Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds....
 such as Chlamydomonas
Chlamydomonas

Chlamydomonas is a genus of green alga. They are unicellular flagellates. Chlamydomonas is used as a model organism for molecular biology, especially studies of flagellum motility and chloroplast dynamics, biogenesis, and genetics....
.

In another type, neither of the gametes is flagellated. This is the case for example in the mating of yeast
Mating of yeast

The yeast Saccharomyces cerevisiae is a simple Microorganism eukaryote with both a diploid and haploid mode of existence. The mating of yeast only occurs between haploids, which can be either the a or a mating type and thus display simple sexual differentiation....
. Yeast mating types are commonly noted as "a" and "a" (alpha) instead of "+" and "-".

Another, more complex form, is conjugation
Conjugation

Conjugation may refer to:*Grammatical conjugation, the modification of a verb from its basic form, including:**Latin conjugation**Spanish conjugation...
. This occurs in some green algae, for example in Spirogyra
Spirogyra

Spirogyra is a genus of filamentous green algae of the order Zygnematales, named for the helix or spiral arrangement of the chloroplasts that is diagnostic of the genus....
. These algae grow as filaments of cells. When two filaments of opposing mating types come close together, the cells form conjugation tubes between the filaments. Once the tubes are formed, one cell balls up and crawls through the tube into the other cell to fuse with it, forming a zygote.

Fungi
Fungus

A fungus is a Eukaryote organism that is a member of the Kingdom Fungi . The fungi are a monophyletic group, also called the Eumycota , that is phylogeny distinct from the morphologically similar slime molds and water molds ....
 also use conjugation. In zygomycetes, two hyphae of opposing mating types form special structures called gametangia
Gametangia

A gametangium is an Organ or cell in which gametes are produced that is found in many multicellular protists, algae, Fungus, and the gametophytes of plants....
 where the hyphae touch. The gametangia then fuse into a zygosporangium. In other fungi, cells from two hyphae with opposing mating types fuse, but only cytoplasmic (plasmogamy
Plasmogamy

Plasmogamy is a stage in the sexual reproduction of fungi. In this stage, the cytoplasm of two parent mycelia fuse together without the fusion of nuclei, as occurs in higher terrestrial fungi....
). The two nuclei do not fuse, leading to the formation of a dikaryon
Dikaryon

Dikaryon is from Greek language, di meaning 2 and karyon meaning Nut , referring to the cell nucleus.The dikaryon is a nuclear feature which is unique to some fungi, in which after plasmogamy the two compatible nuclei of two cell pair off and cohabit without karyogamy within the cells of the hyphae, synchronous dividing so that...
 cell that gives rise to a mycelium
Mycelium

Mycelium is the Vegetative reproduction part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the Fairy rings fungi....
 consisting of dikaryons. Karyogamy
Karyogamy

Karyogamy is the fusion of pronuclei of two cell s, as part of syngamy. It is one of the two major modes of reproduction in fungi. It is also the fusion of the pronuclei of two cells, as occurs in fertilization or true bacterial conjugation......
 (fusion of nuclei) occurs in sporangia and leads to the formation of diploid cells (zygotes) that immediately undergo meiosis
Meiosis

In biology or life science, meiosis is a process of reductional division in which the number of chromosomes per cell is halved. In animals, meiosis always results in the formation of gametes, while in other organisms it can give rise to spores....
 to form spore
Spore

In biology, a spore is a reproduction structure that is adapted for biological dispersal and surviving for extended periods of time in unfavorable conditions....
s.

In many cases, isogamous fertilization is used by organisms that can also reproduce asexually through binary fission
Binary fission

Binary fission is the form of asexual reproduction and cell division used by prokaryotic and some eukaryotic organisms . This process results in the reproduction of a living prokaryotic cell by division into two parts which each have the potential to grow to the size of the original cell....
, budding
Budding

Budding is the formation of a new organism by the protrusion of part of another organism. This is very common in plants and fungi, but may be found in some animals as well, such as the Hydra ....
, or asexual spore formation. The switch to sexual reproduction
Sexual reproduction

Sexual reproduction is characterized by processes that pass a Genetic recombination of Genetics material to offspring, resulting in Genetic diversity....
 mode is often triggered by a change from favorable to unfavorable growing conditions. Fertilization frequently leads to the formation of a thick-walled zygotic resting spore
Resting spore

A spore created by fungi which is thickly encysted in order to survive through stressful times, such as drought.*Protects the spore from biotic , as well as abiotic factors....
 that can withstand harsh environments and will germinate once growing conditions turn favorable again.

Isogamy in Social Anthropology

The term isogamy is also used in anthropology to refer to marriage
Marriage

Marriage is a social, spirituality, or law union of individuals. This union may also be called matrimony, while the ceremony that marks its beginning is usually called a wedding and the married status created is sometimes called wedlock....
 between people of equal social status
Social status

In sociology or anthropology, social status is the honor or prestige attached to one's position in society . The stratification system, which is the system of distributing rewards to the members of society, determines social status....
 or caste
Caste

Castes are hereditary systems of wikt:occupation, endogamy, culture, social class, and political power, the assignment of individuals to places in the social hierarchy is determined by social group and culture....
.

See also

Gamete
Gamete

A gamete is a Cell that fuses with another gamete during fertilization in organisms that sexual reproduction. In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete?called an ovum ?and a male produces th...
 Anisogamy
Anisogamy

Anisogamy refers to a form of sexual reproduction involving gametes of different sizes. The smaller gamete is considered to be male whereas the larger gamete is regarded as female ....