Biology, URE-ZYG
How do plants feed themselves? How did dogs evolve from wolves? What good is the appendix in humans, anyway? Such questions fall within the domain of biology, which seeks to understand living organisms and their vital processes (although the jury’s still out on what our appendixes are for). Biology’s diverse fields include botany, ecology, evolution, genetics, medicine, physiology, and zoology.
Biology Encyclopedia Articles By Title
urethritis, infection and inflammation of the urethra, the channel for passage of urine from the urinary bladder......
urinary bladder, in most vertebrates, except birds, organ for the temporary storage of urine from the kidneys,......
urinary tract infection (UTI), in humans, inflammation of the renal system characterized by frequent and painful......
urinary tract obstruction, blockage or constriction at any point in the urinary tract that impedes the normal flow......
urination, the process of excreting urine from the urinary bladder. Nerve centres for the control of urination......
urine, liquid or semisolid solution of metabolic wastes and certain other, often toxic, substances that the excretory......
urogenital malformation, any defect in the organs and tissues responsible for the formation and excretion of urine......
urogenital system, in vertebrates, the organs concerned with reproduction and urinary excretion. Although their......
uterus, an inverted pear-shaped muscular organ of the female reproductive system, located between the bladder and......
uveitis, inflammation of the uvea (or uveal tract), the middle layer of tissue surrounding the eye that consists......
vaccine-associated feline sarcoma, malignant tumour of cats that develops at the site of a vaccine injection. The......
vacuole, in biology, a space within a cell that is empty of cytoplasm, lined with a membrane, and filled with fluid.......
vagina, canal in female mammals that receives the male reproductive cells, or sperm, and is part of the birth canal......
vaginitis, inflammation of the vagina, usually due to infection. The chief symptom is the abnormal flow of a whitish......
variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species......
Vaucheria, genus of yellow-green algae (family Vaucheriaceae), found nearly worldwide. Most species occur in fresh......
veganism, the theory or practice of abstaining from the consumption and use of animal products. While some vegans......
vegetarianism, the theory or practice of living solely upon vegetables, fruits, grains, legumes, and nuts—with......
ventricle, muscular chamber that pumps blood out of the heart and into the circulatory system. Ventricles occur......
ventricular septal defect, opening in the partition between the two ventricles, or lower chambers, of the heart.......
vertebral column, in vertebrate animals, the flexible column extending from neck to tail, made of a series of bones,......
vertigo, sensation of spinning or tilting or that one’s surroundings are rotating. Usually the state produces dizziness,......
vesicular exanthema of swine, viral disease of swine causing eruption of painful blisters on feet and snout. Blisters......
vesicular stomatitis, viral disease causing blisters in the mouths of cattle, horses, and mules and on the snouts......
vesiculitis, inflammation and infection of the seminal vesicles in the male reproductive tract. The seminal vesicles......
vestibular system, apparatus of the inner ear involved in balance. The vestibular system consists of two structures......
vestibulo-ocular reflex (VOR), eye movement that functions to stabilize gaze by countering movement of the head.......
vestibulocochlear nerve, nerve in the human ear, serving the organs of equilibrium and of hearing. It consists......
villus, in anatomy any of the small, slender, vascular projections that increase the surface area of a membrane.......
viral disease, disease caused by viruses. Long-term immunity usually follows viral childhood diseases (see chickenpox).......
virion, an entire virus particle, consisting of an outer protein shell called a capsid and an inner core of nucleic......
virology, branch of microbiology that deals with the study of viruses. Although diseases caused by viruses have......
virus, infectious agent of small size and simple composition that can multiply only in living cells of animals,......
- Introduction
- Structure, Capsid, Genome
- Protein Capsid, Structure, Infection
- Infection, Host, Replication
- Integration, Replication, Host Cells
- Malignant Transformation
- Infection, Structure, Replication
- Latency, Infection, Replication
- Prevention, Vaccines, Hygiene
- Evolution, Strains, Mutations
- Annotated classification
vision, physiological process of distinguishing, usually by means of an organ such as the eye, the shapes and colours......
visual field defect, a blind spot (scotoma) or blind area within the normal field of one or both eyes. In most......
visual pigment, any of a number of related substances that function in light reception by animals by transforming......
vitalism, school of scientific thought—the germ of which dates from Aristotle—that attempts (in opposition to mechanism......
vitiligo, patchy loss of melanin pigment from the skin. Though the pigment-making cells of the skin, or melanocytes,......
viviparity, retention and growth of the fertilized egg within the maternal body until the young animal, as a larva......
What do you think? Explore the ProCon debate vivisection, operation on a living animal for experimental rather......
vocal cord, either of two folds of mucous membrane that extend across the interior cavity of the larynx and are......
vocal sac, the sound-resonating throat pouch of male frogs and toads (amphibians of the order Anura). Vocal sacs......
vocalization, any sound produced through the action of an animal’s respiratory system and used in communication.......
Volkmann contracture, disorder of the wrist and hand in which the hand and fingers become fixed in a characteristic......
volvocid, any of a group of green algae (division Chlorophyta) that are common in fresh water. Colonies vary from......
Volvox, genus of some 20 species of freshwater green algae (division Chlorophyta) found worldwide. Volvox form......
vomiting, the forcible ejection of stomach contents from the mouth. Like nausea, vomiting may have a wide range......
von Willebrand disease, inherited blood disorder characterized by a prolonged bleeding time and a deficiency of......
vulva, the external female genitalia that surround the opening to the vagina; collectively these consist of the......
vulvitis, inflammation and infection of the vulva—the external genitalia of the female. The external organs of......
warm-bloodedness, in animals, the ability to maintain a relatively constant internal temperature (about 37° C [99°......
wart, a well-defined growth of varying shape and size on the skin surface caused by a virus, most commonly one......
West Nile virus, virus belonging to the family Flaviviridae, related to viruses that can cause yellow fever and......
Allergic reactions are caused by substances known as allergens. These substances can be found in a variety of sources......
white blood cell, a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility,......
white nose syndrome, disease affecting hibernating bats in North America that is caused by the growth of a white......
whooping cough, acute, highly communicable respiratory disease characterized in its typical form by paroxysms of......
Bees are crucial to our world for several reasons, primarily due to their role as pollinators. The approximately......
Plants are green because of a pigment found in the chloroplasts of plant cells called chlorophyll. It plays a crucial......
Different blood groups are the result of genetic variations that determine the presence or absence of specific......
The long neck of a giraffe (genus Giraffa) is a classic example of adaptation, which is the process by which a......
As snakes grow, their skin does not grow with them. Instead, they periodically shed their outer layer of skin to......
wilt, common symptom of plant disease resulting from water loss in leaves and stems. Affected parts lose their......
witches’-broom, symptom of plant disease that occurs as an abnormal brushlike cluster of dwarfed weak shoots arising......
wound, a break in the continuity of any bodily tissue due to violence, where violence is understood to encompass......
Xanthophyta, division or phylum of algae commonly known as yellow-green algae...
xeroderma pigmentosum, rare, recessively inherited skin condition in which resistance to sunlight and other radiation......
Xg blood group system, classification of human blood based on the presence of proteins called Xg antigens on the......
yaws, contagious disease occurring in moist tropical regions throughout the world. It is caused by a spirochete,......
yeast, any of about 1,500 species of single-celled fungi, most of which are in the phylum Ascomycota, only a few......
yellow-green algae, (class Xanthophyceae), class of approximately 600 species of algae in the division Chromophyta,......
Yersinia, (genus Yersinia), any of a group of ovoid- or rod-shaped bacteria of the family Enterobacteriaceae. Yersinia......
yersiniosis, acute gastrointestinal infection caused by the bacterium Yersinia enterocolitica and characterized......
Yt blood group system, classification of human blood based on the presence of molecules known as Yt antigens on......
Zellweger syndrome, congenital disorder characterized by complete absence or reduction in the number of peroxisomes......
Zika virus, infectious agent of the genus Flavivirus in the family Flaviviridae. Zika virus was first isolated......
zoo, place where wild animals and, in some instances, domesticated animals are exhibited in captivity. In such......
zoochlorella, small green alga (often Chlorella) or, sometimes, flagellate protozoan (e.g., Tetraselmis, Carteria)......
zooflagellate, any flagellate protozoan that is traditionally of the protozoan class Zoomastigophorea (sometimes......
zoogeography, the branch of the science of biogeography (q.v.) that is concerned with the geographic distribution......
zoology, branch of biology that studies the members of the animal kingdom and animal life in general. It includes......
zoonotic disease, any of a group of diseases that can be transmitted to humans by nonhuman vertebrate animals,......
zooplankton, small floating or weakly swimming organisms that drift with water currents and, with phytoplankton,......
zooxanthella, flagellate protozoan (or alga) with yellow or brown pigments contained in chromatophores that lives......
zygote, fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm).......
