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. A female individual cannot reprodu ...
The word chromosome comes from the Greek χρ?μα (chroma, "colour") and σ?μα (soma, "body"). Chromatin and chromosomes, are both very strongly stained by particular dyes.Schleiden, Virchow and ...
The study of reproduction and development in organisms was carried out by many botanists and zoologists.Wilhelm Hofmeister demonstrated that alternation of generations is a feature that unites plants, ...
The gender taxonomy is a classification of the range of different levels at which humans vary in sexual characteristics. It is mainly used by medical specialists working in the area of sex research. J ...
G. tigrina individuals are around 10 mm in length. They have a head with two broad and short auricles. The two eyes are in two pigment-free patches. The dorsal surface of the body has numerous pigment ...
The oldest known platyhelminth specimen is a fossil preserved in Eocene age Baltic amber and placed in the monotypic species Micropalaeosoma balticus, while the oldest subfossil specimens are schistos ...
Platyhelminthes are bilaterally symmetrical animals: their left and right sides are mirror images of each other; this also implies they have distinct top and bottom surfaces and distinct head and tail ...
The blacktip shark was first described by French zoologist Achille Valenciennes as Carcharias (Prionodon) limbatus in Johannes Müller and Friedrich Henle's 1839 Systematische Beschreibung der Plagios ...
According to the Oxford English Dictionary, the word is derived from Latin hybrida, meaning the "offspring of a tame sow and a wild boar", "child of a freeman and slave", etc. The term entered into po ...
Problems in taxonomic classificationAlthough Fungi imperfecti/Deuteromycota is no longer formally accepted as a taxon, many of the fungi it included have yet to find a place in modern fungal classific ...
The genus name originated from the Greek language and refers to a beard-like structure, the psammophore, below the head (Greek π?γων/pōgōn, "beard" + μ?ρμηξ/murmēx, "ant"), which can be ...
Modern philosophical-scientific thinking on the problem can be traced back to Erasmus Darwin in the 18th century; it also features in Aristotle's writings. The thread was later picked up by August Wei ...
Gynodioecy is a dimorphic breeding system in which male-sterile individuals (i.e. females) coexist with hermaphroditic individuals in populations. For example, populations of Lobelia siphilitica and L ...
The fitness requirements for androdioecy to arise and sustain itself are theoretically so improbable that it was long considered that such systems do not exist. Particularly, males and hermaphrodites ...
Fraxinus lanuginosa (Japanese Ash; Japanese: アオダモ Aodamo) is a species of ash native to Japan and to the Primorye region of eastern Russia.Fraxinus lanuginosais a medium-sized deciduous tree growi ...
