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Tonka bean

The tonka bean is the seed of Dipteryx odorata, a species of flowering tree in the pea family Fabaceae. They are black and wrinkled and have a smooth brown center.

                                               

Topoisomerase

A topoisomerase is one of a group of enzymes that unwind and wind DNA in order to help the creation of DNA structures. DNA is in a helix/spiral which helps make the structure of DNA strong and stable. However, when undergoing DNA replication, the ...

                                               

Toucan

The toucan is a South American bird in the family Ramphastidae. This social bird lives in small flocks in lowland rainforests in countries such as Costa Rica. It flies short distances between trees. Toucans rest in holes in trees. They mostly eat ...

                                               

Transduction (physiology)

In physiology, transduction is the change of a stimulus from one form to another. Transduction in the nervous system typically means synaptic events where an electrical signal is converted into a chemical one by the release of neurotransmitters. ...

                                               

Trees of Pakistan

In Pakistan the more than 430 tree species are on 82 families and 226 genera. Out of these 22 species from 5 families and 11 genera belong to softwood trees of gymnosperms. The Himalayan Deodar Cedar is the" National Tree of Pakistan”. Below is a ...

                                               

Trench foot

Trench foot or fat foot is a medical condition that is caused by keeping feet in the cold, in dirty places, or in water for a long time. Trench foot was a big problem in the trenches of World War I. Many of the soldiers fighting got this conditio ...

                                               

Triatominae

The members of Triatominae are a subfamily of Reduviidae. They are also called kissing bugs, conenose bugs, assassin bugs or triatomines. There are more than 130 species in this subfamily. Most of them feed on vertebrate blood. A few species feed ...

                                               

Trifolium pratense

Red Clover is a species of plant. It is native to Europe, Africa, and Asia. It has been introduced to North America, Hawaii, and Puerto Rico. It blooms from spring to early fall. It is found in fields, pastures, and near roadsides. Red Clover lik ...

                                               

Triodia

Triodia is a large genus of grass endemic to Australia. They are often called spinifex, but they are not a part of the genus Spinifex, which is only found near the coast. There are 64 known species. Triodia is a perennial grass that grows in dry ...

                                               

Triphyophyllum

Triphyophyllum is a carnivorous plant genus with only one species Triphyophyllum peltatum. It is native to tropical western Africa, in Sierra Leone and Liberia, growing in tropical rainforests. It is a liana, with a three-stage lifecycle, each wi ...

                                               

Tumors of the hematopoietic and lymphoid tissues

Blood cancer is a type of cancer or tumor. Blood cancer hurts the blood, bone marrow, lymph, and lymphatic system. Sometimes more than one body part is hurt. The cause is usually different from other types of cancer. The way to find out if a pers ...

                                               

Tuna

Tuna, sometimes called tuna fish, are several species of fish. They are in the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers. People have seen tuna swim at up to 77 km/h. Several species of tuna are warm-blooded. Most spe ...

                                               

Turbot

Turbot is a large flatfish. It is a demersal fish which lives in marine or brackish waters. It is found in the North Atlantic, Baltic Sea and the Mediterranean Sea. Turbot are fished for food, and have a delicate flavour. They are farmed in a num ...

                                               

Turkey (bird)

Turkeys are a family of bird in the genus Meleagrididae. They are like a chicken but much bigger. Wild turkeys live in forests in North America and Central America. In the United States, people traditionally eat turkey on the holiday of Thanksgiv ...

                                               

Turkey vulture

The turkey vulture, is a bird found throughout most of the Americas. It is also known as the turkey buzzard, and in some areas of the Caribbean as John crow or carrion crow. It is one of three species in the genus Cathartes, ranging from southern ...

                                               

Turmeric

Turmeric is a spice, widely used in Asian cooking. It is a rhizomatous herbaceous perennial plant, in the ginger family, Zingiberaceae.

                                               

Type specimen

In biology, a type specimen is a particular specimen to which a scientific name is formally attached. For this purpose a specimen is something that can be kept, unchanging, for a long time. A specimen may be an organism, a part of an organism, or ...

                                               

Typha

Typha is a genus of plants. They are found in wetland habitats. They are commonly found in the Northern Hemisphere, but may be found in wetlands elsewhere. These plants are known in British English as bulrush, bullrush or reedmace, and in America ...

                                               

Typhoid

Other unrelated diseases with a similar name are typhus and paratyphoid fever Typhoid, also called typhoid fever, is not an illness caused by the bacterium Salmonella Typhi. The disease is spread through water which has the Salmonella Typhi bacte ...

                                               

Typhus

Typhus is unrelated to both typhoid fever and paratyphoid fever Typhus is the name for a number of diseases, caused by bacteria called Rickettsiae. These bacteria are parasites that cannot survive outside their host organism. Depending on the spe ...

                                               

Tyrannosauridae

Tyrannosauridae is a taxonomic family of theropods. These dinosaurs from the Upper Cretaceous have been found only in North America and Asia. They lived in the later part of the period, 88 to 65 million years ago.

                                               

Ulcer

An ulcer is a kind of open wound. Ulcers can be on surfaces of the body. They can be on skin. They can be mucous membranes like the surface of the stomach or inside the mouth. Ulcers start when the top layer surface of skin or mucous membrane is ...

                                               

Umbilicus

The umbilicus is a place on the body of mammals that is left after a baby loses its umbilical cord. The umbilicus of humans is in the middle of the abdomen. It is usually only easy to see on humans, and is a thin line on many other mammals. In hu ...

                                               

Ungulate

Ungulates are several groups of mammals. Most of them use the tips of their toes, usually as hooves, to support their body weight while moving. As a descriptive term, "ungulate" normally excludes cetaceans, because they do not have most of the ty ...

                                               

Upper Amazon tree frog

The upper Amazon tree frog is a frog that lives in the upper Amazon basin. This is in parts of Ecuador, Colombia, Peru, Brazil and Bolivia. The adult male frog is 2.3 to 2.8 cm long and the adult female frog is 2.9 to 3.5 cm long. This frog is br ...

                                               

Uremia

Uremia is a Greek word used in English to describe the condition of a persons blood. Uremia is caused by urine products building up in the blood. If those come over the normal filtration system of the kidneys then the condition is called uremia. ...

                                               

Urticaceae

Urticaceae the nettle family comprising about 45 genera of herbs, shrubs, small trees, and a few vines, distributed primarily in tropical regions. The family is typical of the nettle order.

                                               

Vaginal discharge

Vaginal discharge is the fluid coming out of the vagina. It can be clear or different colors, white, yellow or green. It can be different thicknesses. Most of the time clear discharge is normal. Clear discharge is part of the menstrual cycle. Som ...

                                               

Vampire bat

Vampire bats is a subfamily of bats. Unlike other bats, vampire bats feed on blood. Currently, there are three species of bats known to do this. All of them live in the Americas, in Mexico, Brazil, Chile and Argentina. Of the three known species, ...

                                               

Variable Antshrike

The variable antshrike is a species of bird in the Thamnophilidae family found most in South America. It is arguably the species of antbird with the most variable plumage. This leads to claims that it includes more than one species, but evidence ...

                                               

Variation

Variation in biology usually refers to the heritable differences within a species. This is important in genetics, and the study of evolution in natural populations. Heritable variation is ultimately caused by mutations of genes and chromosomes, a ...

                                               

Vascular cambium

The vascular cambium is a lateral meristem. It is the source of both the secondary xylem inwards, towards the pith and the secondary phloem outwards, and is between these tissues in the stem and root. Only a few leaves even have a vascular cambiu ...

                                               

Vascular dementia

Vascular dementia is the second most common form of dementia after Alzheimers disease. It is a type of dementia caused by problems in the supply of blood to the brain. Brain cells need a good supply of blood to stay healthy and function properly. ...

                                               

Vasoactive intestinal peptide

Vasoactive intestinal peptide is a kind of hormone that has 28 amino acid residues in it and is made in many areas of the human body including the gut, pancreas, and suprachiasmatic nuclei of the hypothalamus in the brain. In humans, the vasoacti ...

                                               

Vasoconstriction

Vasoconstriction occurs when blood vessels become narrower because of the tightening of the muscles in their walls. Its opposite is vasodilation, which is when blood vessels widen. For example, when you are cold, blood vessels near the skin vasoc ...

                                               

Vegavis

Vegavis is a genus of extinct bird that lived during the latest Upper Cretaceous of Antarctica, some 66 million years ago. Among modern birds, It is most closely related to ducks and geese. The discovery shows that some of the major groups of bir ...

                                               

Vein

A vein is a type of blood vessel in the body. All veins carry blood to the heart. Most veins carry blood that is low in oxygen, except for the pulmonary vein and the umbilical veins which carry blood that is high in oxygen. A vein has a large lum ...

                                               

Venezuelan Sylph

The Venezuelan sylph is a species of hummingbird. It is restricted to a small area of north-eastern Venezuela and is classed as an endangered species by BirdLife International. It is sometimes thought to be a subspecies of the Long-tailed Sylph. ...

                                               

Veragua cross-banded tree frog

The Veragua cross-banded treefrog or drab treefrog is a frog that lives in Honduras, Nicaragua, Panama, Costa Rica and Colombia. Scientists have seen it as high in the hills as 1525 meters above sea level. The adult male frog is 3.62 cm long and ...

                                               

Verdin

The Verdin is a small bird. It is the only species in the genus Auriparus, and the only species in the family found in the New World. The Verdin is a very small bird. At 4.5 inches in length, it rivals the Bushtit as one of the smallest passerine ...

                                               

Vesicle

A vesicle is a bubble of liquid within a cell. More technically, a vesicle is a small, intracellular, membrane-enclosed sac that stores or transports substances within a cell. Vesicles form naturally because of the properties of lipid membranes. ...

                                               

Vesper bat

The Vesper bat is a species of bat belonging to the Microchiroptera family. It is the largest and most well-known species belonging to that family. The bats can be found in different parts of all continents except Antarctica. They are thought to ...

                                               

Villi

Villi are small, finger-like structures in the small intestine. They help to absorb digested food. Each villus has microvilli which increase the surface area of the intestinal walls. A larger surface area allows nutrients to be taken in more quic ...

                                               

Viral infection

A viral infection occurs when a living things body is entered in an unwanted way by disease-causing viruses, and able to be caught from others virus particles attach to and enter susceptible cells.

                                               

Viscacha

Viscachas or vizcachas are rodents. Together with the chinchilla they make up the family Chinchillidae. There are two genera and four species of viscacha. Plains viscacha Lagostomus maximus: Lives in the Pampas of Argentina and Chile. It can be e ...

                                               

Vitaceae

Vitaceae are a family of dicotyledonous flowering plants including the grape and Virginia creeper. The family name comes from the genus Vitis. The name sometimes appears as Vitidaceae, but Vitaceae is a conserved name and therefore has priority o ...

                                               

Viviparity

Vivparous animals have internal fertilisation and the eggs develop inside the mother. The key idea is that the growing embryo gets its nutrition from a placenta in the mothers womb. It is the standard method for all mammals except monotremes.

                                               

Vulture

Vultures are large birds of prey that usually feed on carrion. Vultures use their large wings to soar in the air for many miles without having to flap. Vultures are also called buzzards. Vultures from the Old World are not related to the vultures ...

                                               

Vulva

The vulva is the part of the body of female mammals where the outside parts of the reproductive system can be seen. The parts of the vulva that can be seen are the: Labia majora Labia minora Mons pubis Clitoris Urinary opening Vaginal opening The ...

                                               

Wakaleo schouteni

Wakaleo schouteni is an extinct marsupial that once lived in Australia. It is closely related to the marsupial lion, Thylacoleo carnifex, which lived until 30.000 years ago. Wakaleo schouteni is estimated to have become extinct about 19 million y ...