Mayflies are insects assigned to the Order Ephemeroptera. They are related to dragonflies and damselflies. Their development takes place in freshwater and typically takes a year. During that time, they are known as "nymphs". The adults are short-lived, from a few hours to a few days depending on the species. About 2,500 species are known worldwide. Depicted here is a female subimago of the March Brown, Rhithrogena germanica, which is a faunistic rarity and on the red list of endangered species.
Biodiversity is the diversity of and in living nature. Diversity, at its heart, implies the number of different kinds of objects, such as species. To increase the genetic diversity of U.S.corn, the Germplasm Enhancement for Maize (GEM) project seeks to combine exotic germplasm, such as this unusually colored and shaped maize from Latin America, with domestic corn lines.
A mating pair of European or Common Toads(Bufo bufo) occupying the position known as amplexus. This is indeed a common toad, with a range that includes North Africa, Europe except Ireland, and across North Asia into Siberia. In some regions, toads are threatened by roads disrupting their spawning migrations, and in many places, tunnels have been built to allow them to cross roads.
Three types of cell reproduction are compared: the relatively simple binary fission and two more complicated types that either involve mitosis or meiosis.
March 1, 2006
Fruit of the Horse Chestnut tree. The dried seeds are often used in the English children's game: Conker.
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