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Desert Ants
''Cataglyphis'' is a genus of ant, desert ants, in the subfamily Formicinae. Its most famous species is ''C. bicolor'', the Sahara Desert ant, which runs on hot sand to find insects that died of heat exhaustion, and can, like other several other ''Cataglyphis'' species, sustain body temperatures up to 50°C. Cataglyphis is also the name of an autonomous rover that won the NASA Sample Return Robot Centennial Challenge inspired by the navigation approaches used by desert ants. Name It was named in 1850, with reference to the impressions of its abdomen: "Von χατά und γλυψίς der Einschnitt. Eine Andeutung auf die vielen Einschnitte oder vielmehr Eindrücke de Hinterleibs." Description Species of this genus are behaviourally, morphologically, and physiologically adapted to dry and hot habitats. Navigational behaviour In the Sahara, ants live where no bushes or clumps of grass are available to protect them, and where tracks are covered by wind-blown sand in seconds. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greece
Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to the east. The Aegean Sea lies to the east of the Geography of Greece, mainland, the Ionian Sea to the west, and the Sea of Crete and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin, spanning List of islands of Greece, thousands of islands and nine Geographic regions of Greece, traditional geographic regions. It has a population of over 10 million. Athens is the nation's capital and List of cities and towns in Greece, largest city, followed by Thessaloniki and Patras. Greece is considered the cradle of Western culture, Western civilisation and the birthplace of Athenian democracy, democracy, Western philosophy, Western literature, historiography, political science, major History of science in cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataglyphis Abyssinica
''Cataglyphis'' is a genus of ant, desert ants, in the subfamily Formicinae. Its most famous species is ''C. bicolor'', the Sahara Desert ant, which runs on hot sand to find insects that died of heat exhaustion, and can, like other several other ''Cataglyphis'' species, sustain body temperatures up to 50°C. Cataglyphis is also the name of an autonomous rover that won the NASA Sample Return Robot Centennial Challenge inspired by the navigation approaches used by desert ants. Name It was named in 1850, with reference to the impressions of its abdomen: "Von χατά und γλυψίς der Einschnitt. Eine Andeutung auf die vielen Einschnitte oder vielmehr Eindrücke de Hinterleibs." Description Species of this genus are behaviourally, morphologically, and physiologically adapted to dry and hot habitats. Navigational behaviour In the Sahara, ants live where no bushes or clumps of grass are available to protect them, and where tracks are covered by wind-blown sand in seconds. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilisation
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or offspring. While processes such as insemination or pollination, which happen before the fusion of gametes, are also sometimes informally referred to as fertilisation, these are technically separate processes. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms, the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygote
A zygote (; , ) is a eukaryote, eukaryotic cell (biology), cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. The sexual fusion of haploid cells is called karyogamy, the result of which is the formation of a Ploidy#Haploid and monoploid, diploid cell called the zygote or zygospore. History German zoologists Oscar Hertwig, Oscar and Richard Hertwig made some of the first discoveries on animal zygote formation in the late 19th century. In multicellular organisms The zygote is the earliest developmental stage. In humans and most other Anisogamy, anisogamous organisms, a zygote is formed when an egg cell and sperm, sperm cell come together to create a new unique organism. The formation of a cell potency, totipotent zygote with the potential to produce a whole organism depends on epigenetics, epigenetic reprogramming. DNA demethyla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one copy of each chromosome (haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and a female will fuse to create a zygote, a cell with two copies of each chromosome. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thelytoky
Thelytoky (from the Ancient Greek, Greek θῆλυς ''thēlys'' "female" and τόκος ''tókos'' "birth") is a type of parthenogenesis and is the absence of mating and subsequent production of all female diploid offspring as for example in aphids. Thelytokous parthenogenesis is rare among animals and reported in about 1,500 species, about 1 in 1000 of described animal species, according to a 1984 study. It is more common in invertebrates, like arthropods, but it can occur in vertebrates, including salamanders, fish, and reptiles such as some Cnemidophorus, whiptail lizards. Thelytoky can occur by different mechanisms, each of which has a different impact on the level of zygosity, homozygosity. It is found in several groups of Hymenoptera, including Apidae, Aphelinidae, Cynipidae, Formicidae, Ichneumonidae, and Tenthredinidae. It can be induced in Hymenoptera by the bacteria ''Wolbachia'' and ''Cardinium''. Advantages of thelytoky Species may encounter a few advantages employ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis
Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertilized Gametophyte, egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg. Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea, and parasitic wasps), and a few vertebrates, such as some fish, amphibians, and reptiles. This type of reproduction has been induced artificially in animal species that naturally reproduce through sex, including fish, amphibians, and mice. Normal egg cells form in the process of meiosis and are haploid, with half as many chromosomes as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyne
The gyne (, from Greek γυνή, "woman") is the primary reproductive female caste of social insects (especially ants, wasps, and bees of order Hymenoptera, as well as termites). Gynes are those destined to become queens, whereas female workers are typically barren and cannot become queens. Having a queen is what makes a "queenright" hive, nest, or colony of eusocial insects. A colony with multiple queens is said to be a polygyne form, whereas one with only one is a monogyne form. The ancient Greek origin of ''gyne'' meant a woman who had given birth to at least one child. In species lacking morphological castes (i.e., where "workers" may not be sterile), the term "gyne" is usually reserved for those females whose entire life is spent as a reproductive or potential reproductive, as opposed to those who start life as a worker and subsequently attain reproductive status (often called a "replacement queen" or a "laying worker"). These can be seen in certain species of stingless be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspian Sea
The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau. It covers a surface area of (excluding the highly saline lagoon of Garabogazköl to its east), an area approximately equal to that of Japan, with a volume of . It has a salinity of approximately 1.2% (12 g/L), about a third of the salinity of average seawater. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the southwest, Iran to the south, and Turkmenistan to the southeast. The name of the Caspian Sea is derived from the ancient Iranian peoples, Iranic Caspians, Caspi people. The sea stretches from north to south, with an average width of . Its gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aral Sea
The Aral Sea () was an endorheic lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and had largely dried up into desert by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. The name roughly translates from Mongolic and Turkic languages to "Sea of Islands", a reference to the large number of islands (over 1,100) that once dotted its waters. The Aral Sea drainage basin encompasses Uzbekistan and parts of Afghanistan, Iran, Kazakhstan, Kyrgyzstan, Tajikistan, and Turkmenistan. Formerly the third-largest lake in the world with an area of , the Aral Sea began shrinking in the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007, it had declined to 10% of its original size, splitting into four lakes: the North Aral Sea, the eastern and western basins of the once far larger South Aral Sea, and the smaller intermediate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
