Birds are a group of warm-blooded vertebrates constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m common ostrich. There are over 11,000 living species, more than half of which are passerine, or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. The study of birds is called ornithology.
A chordate is a deuterostomic animal belonging to the phylum Chordata. All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (synapomorphies) that distinguish them from other taxa. These five synapomorphies are a notochord, a hollow dorsal nerve cord, an endostyle or thyroid, pharyngeal slits, and a post-anal tail. The name "chordate" comes from the first of these synapomorphies, the notochord, which plays a significant role in chordate body plan structuring and movements. Chordates are also bilaterally symmetric, have a coelom, possess a closed circulatory system, and exhibit metameric segmentation.
A video game or computer game is an electronic game that involves interaction with a user interface or input device to generate visual feedback from a display device, most commonly shown in a video format on a television set, computer monitor, flat-panel display or touchscreen on handheld devices, or a virtual reality headset. Most modern video games are audiovisual, with audio complement delivered through speakers or headphones, and sometimes also with other types of sensory feedback. Some video games also allow microphone and webcam inputs for in-game chatting and livestreaming.
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds.
The Eurovision Song Contest, often known simply as Eurovision, is an international song competition organised annually by the European Broadcasting Union. Each participating country submits an original song to be performed live and transmitted to national broadcasters via the Eurovision and Euroradio networks, with competing countries then casting votes for the other countries' songs to determine a winner.
Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and written forms, and may also be conveyed through sign languages. Human language is characterized by its cultural and historical diversity, with significant variations observed between cultures and across time. Human languages possess the properties of productivity and displacement, which enable the creation of an infinite number of sentences, and the ability to refer to objects, events, and ideas that are not immediately present in the discourse. The use of human language relies on social convention and is acquired through learning.
A mammal is a vertebrate animal of the class Mammalia. Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous Period over 300 million years ago. Around 6,400 extant species of mammals have been described and divided into 29 orders.
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the same group tend to show similar chemical characteristics.
Sex is the trait that determines whether a sexually reproducing organism produces male or female gametes. During sexual reproduction, a male and a female gamete fuse to form a zygote, which develops into an offspring that inherits traits from each parent. By convention, organisms that produce smaller, more mobile gametes are called male, while organisms that produce larger, non-mobile gametes are called female. An organism that produces both types of gamete is hermaphrodite.
The Academy Award for Best Picture is one of the Academy Awards presented annually by the Academy of Motion Picture Arts and Sciences (AMPAS) since the awards debuted in 1929. This award goes to the producers of the film and is the only category in which every member of the Academy is eligible to submit a nomination and vote on the final ballot. The Best Picture category is traditionally the final award of the night and is widely considered as the most prestigious honor of the ceremony.
A nonprofit organization (NPO), also known as a nonbusiness entity or nonprofit institution, and often referred to simply as a nonprofit, is a legal entity organized and operated for a collective, public or social benefit, as opposed to an entity that operates as a business aiming to generate a profit for its owners. A nonprofit is subject to the non-distribution constraint: any revenues that exceed expenses must be committed to the organization's purpose, not taken by private parties. An array of organizations are nonprofit, including some political organizations, schools, business associations, churches, social clubs, and consumer cooperatives. Nonprofit entities may seek approval from governments to be tax-exempt, and some may also qualify to receive tax-deductible contributions, but an entity may incorporate as a nonprofit entity without having tax-exempt status.
Millennials, also known as Generation Y, are the demographic cohort following Generation X and preceding Generation Z. Researchers and popular media use the early 1980s as starting birth years and the mid-1990s to early 2000s as ending birth years, with the generation typically being defined as people born from 1981 to 1996. Most Millennials are the children of Baby Boomers and older Generation X. In turn Millennials are often the parents of Generation Alpha.
The federal government of the United States is the national government of the United States, a federal republic located primarily in North America, composed of 50 states, five major self-governing territories, several island possessions, and the federal district and national capital of Washington, D.C., where most of the federal government is based.
In basketball, there are five players on court per team, each assigned to positions. Historically, these players have been assigned to positions defined by the role they play on the court, from a strategic point of view. The three main positions are guard, forward, and center, with the standard team featuring two guards, two forwards, and a center. Over time, as more specialized roles developed, each of the guards and forwards came to be differentiated, and today each of the five positions is known by a unique name and number: point guard (PG) or 1, the shooting guard (SG) or 2, the small forward (SF) or 3, the power forward (PF) or 4, and the center (C) or 5 "post position".
An independent, non-partisan politician or non-affiliated politician is a politician not affiliated with any political party or bureaucratic association. There are numerous reasons why someone may stand for office as an independent.
The dog is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf; the gray wolf is the dog's closest living relative. The dog was the first species to be domesticated by humans. Experts estimate that hunter-gatherers domesticated dogs more than 15,000 years ago, which was before the development of agriculture. Due to their long association with humans, dogs have expanded to a large number of domestic individuals and gained the ability to thrive on a starch-rich diet that would be inadequate for other canids.
Social media are interactive technologies that facilitate the creation, sharing and aggregation of content, ideas, interests, and other forms of expression through virtual communities and networks. Social media refer to new forms of media that involve interactive participation. While challenges to the definition of social media arise there are common features:
- Social media apps are online platforms that enable users to create and share content and participate in social networking.
- User-generated content—such as text posts or comments, digital photos or videos, and data generated through online interactions—is the lifeblood of social media.
- Users create service-specific profiles for the website or app that are designed and maintained by the social media organization.
- Social media helps the development of online social networks by connecting a user's profile with those of other individuals or groups.
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia, With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor.
The eukaryotes constitute the domain of Eukarya or Eukaryota, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, and many unicellular organisms are eukaryotes. They constitute a major group of life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes.
