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Western Clawed Frog
The western clawed frog (''Xenopus tropicalis'') is a species of frog in the family Pipidae, also known as tropical clawed frog. It is the only species in the genus ''Xenopus'' to have a diploid genome. Its genome has been sequenced, making it a significant model organism for genetics that complements the related species ''Xenopus laevis'' (the African clawed frog), a widely used vertebrate model for developmental biology. ''X. tropicalis'' also has a number of advantages over ''X. laevis'' in research, such as a much shorter generation time (<5 months), smaller size ( body length), and a larger number of eggs per . It is found in , |
John Edward Gray
John Edward Gray (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Guinea
Equatorial Guinea, officially the Republic of Equatorial Guinea, is a country on the west coast of Central Africa. It has an area of . Formerly the colony of Spanish Guinea, its post-independence name refers to its location both near the Equator and in the Guinea (region), African region of Guinea. , the country had a population of 1,795,834, over 85% of whom are members of the Fang people, the country's dominant ethnic group. The Bubi people, indigenous to Bioko, are the second largest group at approximately 6.5% of the population. Equatorial Guinea consists of two parts. The mainland region, Río Muni, is bordered by Cameroon to the north and Gabon to the south and east. It has the majority of the population and is the location of Bata, Equatorial Guinea, Bata, Equatorial Guinea's largest city, and Ciudad de la Paz, the country's planned future capital. Río Muni's small offshore islands include Corisco, Elobey Grande, and Elobey Chico. The Islands of Equatorial Guinea, ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Four savanna forms exist; ''savanna woodland'' where trees and shrubs form a light canopy, ''tree savanna'' with scattered trees and shrubs, ''shrub savanna'' with distributed shrubs, and ''grass savanna'' where trees and shrubs are mostly nonexistent.Smith, Jeremy M.B.. "savanna". Encyclopedia Britannica, 5 Sep. 2016, https://www.britannica.com/science/savanna/Environment. Accessed 17 September 2022. Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests.Manoel Cláudio da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest
A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a Canopy (biology), canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, ''Global Forest Resources Assessment (FRA), Global Forest Resources Assessment 2020'' found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the largest Terrestrial ecosystem, terrestrial ecosystems of Earth by area, and are found around the globe. 45 percent of forest land is in the Tropical forest, trop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as Biophysical environment, environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and Luminous intensity, light intensity. Biotic index, Biotic factors include the availability of food and the presence or absence of Predation, predators. Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mali
Mali, officially the Republic of Mali, is a landlocked country in West Africa. It is the List of African countries by area, eighth-largest country in Africa, with an area of over . The country is bordered to the north by Algeria, to the east by Niger, to the northwest by Mauritania, to the south by Burkina Faso and Ivory Coast, and to the west by Guinea and Senegal. The population of Mali is about 23.29 million, 47.19% of which are estimated to be under the age of 15 in 2024. Its Capital city, capital and largest city is Bamako. The country has 13 official languages, of which Bambara language, Bambara is the most commonly spoken. The sovereign state's northern borders reach deep into the middle of the Sahara, Sahara Desert. The country's southern part, where the majority of inhabitants live, is in the Sudanian savanna and has the Niger River, Niger and Senegal River, Senegal rivers running through it. The country's economy centres on agriculture and mining with its most promine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Togo
Togo, officially the Togolese Republic, is a country in West Africa. It is bordered by Ghana to Ghana–Togo border, the west, Benin to Benin–Togo border, the east and Burkina Faso to Burkina Faso–Togo border, the north. It is one of the least developed countries and extends south to the Gulf of Guinea, where its capital city, capital, Lomé, is located. It is a small, tropical country, spanning with a population of approximately 8 million, and it has a width of less than between Ghana and its eastern neighbour Benin. Various peoples settled the boundaries of present-day Togo between the 11th and 16th centuries. Between the 16th and 18th centuries, the coastal region served primarily as a Atlantic slave trade, European slave trading outpost, earning Togo and the surrounding region the name "The Slave Coast of West Africa, Slave Coast". In 1884, during the scramble for Africa, German Empire, Germany established a protectorate in the region called Togoland. After World War I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Leone
Sierra Leone, officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered to the southeast by Liberia and by Guinea to the north. Sierra Leone's land area is . It has a tropical climate and environments ranging from savannas to rainforests. As of the 2023 census, Sierra Leone has a population of 8,460,512. Freetown is its capital and largest city. Sierra Leone is a presidential republic, with a unicameral parliament and a directly elected president. It is a secular state. Its Constitution of Sierra Leone, constitution provides for the separation of state and religion and freedom of conscience. Muslims constitute three-quarters of the population, and there is a significant Christian minority. Notably, religious tolerance is very high. Sierra Leone's current territorial configuration was established in two phases: in 1808, the coastal Sierra Leone Colony and Protectorate, Sierra Leone Colony was founded as a place to resettle retu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senegal
Senegal, officially the Republic of Senegal, is the westernmost country in West Africa, situated on the Atlantic Ocean coastline. It borders Mauritania to Mauritania–Senegal border, the north, Mali to Mali–Senegal border, the east, Guinea to Guinea–Senegal border, the southeast and Guinea-Bissau to Guinea-Bissau–Senegal border, the southwest. Senegal nearly surrounds The Gambia, a country occupying a narrow sliver of land along the banks of the Gambia River, which separates Senegal's southern region of Casamance from the rest of the country. It also shares a maritime border with Cape Verde. Senegal's capital is Dakar. Senegal is the westernmost country in the mainland of the Old World, or Afro-Eurasia. It owes its name to the Senegal River, which borders it to the east and north. The climate is typically Sahelian, though there is a wet season, rainy season. Senegal covers a land area of almost and has a population of around 18 million. The state is a Presidential system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nigeria
Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, a population of more than 230 million, it is the List of African countries by population, most populous country in Africa, and the List of countries and dependencies by population, world's sixth-most populous country. Nigeria borders Niger in Niger–Nigeria border, the north, Chad in Chad–Nigeria border, the northeast, Cameroon in Cameroon–Nigeria border, the east, and Benin in Benin–Nigeria border, the west. Nigeria is a Federation, federal republic comprising 36 States of Nigeria, states and the Federal Capital Territory, Nigeria, Federal Capital Territory, where its capital, Abuja, is located. The List of Nigerian cities by population, largest city in Nigeria by population is Lagos, one of the largest List of largest cities, metr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liberia
Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Liberia border, its east, and the Atlantic Ocean to its south and southwest. It has a population of around 5.5million and covers an area of . The official language is English. Languages of Liberia, Over 20 indigenous languages are spoken, reflecting the country's ethnic and cultural diversity. The capital and largest List of cities in Liberia, city is Monrovia. Liberia began in the early 19th century as a project of the American Colonization Society (ACS), which believed that black people would face better chances for freedom and prosperity in Africa than in the United States. Between 1822 and the outbreak of the American Civil War in 1861, more than 15,000 freed and free-born African Americans, along with 3,198 Afro-Caribbeans, relocated to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guinea-Bissau
Guinea-Bissau, officially the Republic of Guinea-Bissau, is a country in West Africa that covers with an estimated population of 2,026,778. It borders Senegal to Guinea-Bissau–Senegal border, its north and Guinea to Guinea–Guinea-Bissau border, its southeast. Guinea-Bissau was once part of the kingdom of Kaabu, as well as part of the Mali Empire. Parts of this kingdom persisted until the 18th century, while a few others had been under some rule by the Portuguese Empire since the 16th century. In the 19th century, it was colonised as Portuguese Guinea. Portuguese control was restricted and weak until the early 20th century, when its pacification campaigns solidified Portuguese sovereignty in the area. The final Portuguese victory over the last remaining bastion of mainland resistance came in 1915, with the conquest of the Papel people, Papel-ruled Kingdom of Bissau by the Portuguese military officer João Teixeira Pinto, Teixeira Pinto and the Wolof people, Wolof mercenary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
