Search results
Results From The WOW.Com Content Network
Isogamy is a form of sexual reproduction that involves gametes of the same morphology (indistinguishable in shape and size), and is found in most unicellular eukaryotes. [1] Because both gametes look alike, they generally cannot be classified as male or female . [ 2 ]
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.
In both plants and animals, gamete size difference is the fundamental difference between females and males. [2] Anisogamy most likely evolved from isogamy. [3] Since the biological definition of male and female is based on gamete size, the evolution of anisogamy is viewed as the evolutionary origin of male and female sexes.
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 ...
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 ...
Mating types are the microorganism equivalent to sex in higher organisms [1] and occur in isogamous species. [2] Depending on the group, different mating types are often referred to by numbers, letters, or simply "+" and "−" instead of "male" and "female", which refer to "sexes" or differences in size between gametes. [1]
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.
Oogamy in animals: small, motile sperm on the surface of an ovum. Oogamy is a form of anisogamy where the gametes differ in both size and form. In oogamy the large female gamete (also known as ovum) is immotile, while the small male gamete (also known as spermatozoon) is mobile. [1]