Search results
Results From The WOW.Com Content Network
It is generally accepted that isogamy is an ancestral state for anisogamy [1] [9]. Isogamous reproduction evolved independently in several lineages of plants and animals into anisogamy (species with gametes of male and female types) and subsequently into oogamy (species in which the female gamete is much larger than the male and has no ability ...
Gametes of both mating individuals can be the same size and shape, a condition known as isogamy. By contrast, in the majority of species, the gametes are of different sizes, a condition known as anisogamy or heterogamy that applies to humans and other mammals. The human ovum has approximately 100,000 times the volume of a single human sperm cell.
Isogamy (Ancient Greek ισο - iso= "equal + γάμος gámos = "marriage") – in cell biology – is a type of sexual reproduction that includes gametes of similar morphological similar shape and size, with difference in general only in genome content and gene expression in one or more mating-type regions.
Differentiation of the gametes. Both gametes the same (isogamy). Like other species of Cladophora, C. callicoma has flagellated gametes which are identical in appearance and ability to move. [20] Gametes of two distinct sizes (anisogamy). Both of similar motility. Species of Ulva, the sea lettuce, have gametes which all have two flagella and so ...
Anisogamy (the opposite of isogamy) comes from the ancient Greek negative prefix a(n)-(alpha privative), the Greek adjective isos (meaning equal) and the Greek verb gameo (meaning to have sex/to reproduce), eventually meaning "non-equal reproduction" obviously referring to the enormous differences between male and female gametes in size and abilities. [10]
Animals have life cycles with a single diploid multicellular phase that produces haploid gametes directly by meiosis. Male gametes are called sperm, and female gametes are called eggs or ova. In animals, fertilization of the ovum by a sperm results in the formation of a diploid zygote that develops by repeated mitotic divisions into a diploid ...
In isogamous species, the gametes are similar or identical in form , but may have separable properties and then may be given other different names (see isogamy). [10] Because both gametes look alike, they generally cannot be classified as male or female. For example, in the green alga, Chlamydomonas reinhardtii, there are so-called "plus" and ...
Isogamous species with two or more mating types with gametes of identical form and behavior (but different at the molecular level), Anisogamous species with gametes of male and female types, Oogamous species, which include humans, in which the female gamete is much larger than the male and has no ability to move. Oogamy is a form of anisogamy. [21]