Biology, 10 -ANX
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
10 Major Epidemics
Throughout history outbreaks of disease have reshaped communities, altered political destinies, and advanced medical......
10 Organisms Named for David Attenborough
With his signature voice and familiar demeanor, naturalist David Attenborough has been hailed as one of the greatest......
10 Ways of Looking at Cells
Since 1665, when English physicist Robert Hooke coined the term cell to describe the microscopic view of cork,......
10 Women Scientists Who Should Be More Famous
Not counting well-known women science Nobelists like Marie Curie or individuals such as Jane Goodall, Rosalind......
10 Women Who Advanced Our Understanding of Life on Earth
The study of life entails inquiry into many different facets of existence, from behavior and development to anatomy......
100+ Animal Fun Facts and Trivia Questions
The animal kingdom is full of remarkable creatures—and even more intriguing questions. Why are flamingos pink?......
1000 Genomes Project
1000 Genomes Project, an international collaboration in which researchers aimed to sequence the genomes of a large......
6 Animal Species that Mate for Life
Lifelong monogamous relationships are common among humans but far less so within the broader animal kingdom. Animals......
6 Animals We Ate Into Extinction
Humans are not always great at self-moderation, especially when things seem both bountiful and tasty. While extinctions......
6 Cell Organelles
Think back to your high school biology class. Do you still remember the names and functions of all those little......
6 Common Infections We Wish Never Existed
We all miss a day of school or work here and there thanks to a cold or a sore throat. But those maladies have nothing......
6 Questions About DNA Answered
Deoxyribonucleic acid, better known as DNA, is crucial to life on Earth. The questions and answers in this list......
7 of the World’s Most Poisonous Mushrooms
Although only a few of the 70-80 species of poisonous mushrooms are actually fatal when ingested, many of these......
8 Zoonotic Diseases
Animals can bring tremendous joy to our lives, but they can also make us sick. Every year, tens of thousands of......
9 Bizarre Myths About Pregnancy
Pregnancy is a time of excitement and anticipation, and mothers-to-be are often brimming with questions, many of......
9 Fun Facts About Sleep
On the outside, we look relaxed, peaceful, and unaware. But what really goes on while we sleep? We spend nearly......
abdominal muscle
abdominal muscle, any of the muscles of the anterolateral walls of the abdominal cavity, composed of three flat......
abductor muscle
abductor muscle, any of the muscles that cause movement of a limb away from the midplane of the body or away from......
abiogenesis
abiogenesis, the idea that life arose from nonlife more than 3.5 billion years ago on Earth. Abiogenesis proposes......
ABO blood group system
ABO blood group system, the classification of human blood based on the inherited properties of red blood cells......
abscess
abscess, a localized collection of pus in a cavity formed from tissues that have been broken down by infectious......
acceleration stress
acceleration stress, physiological changes that occur in the human body in motion as a result of rapid increase......
Acclimatization
Acclimatization, any of the numerous gradual, long-term responses of an organism to changes in its environment.......
Acervulus
Acervulus, an open, saucer-shaped asexual fruiting body found in fungi (kingdom Fungi). Always developed below......
Acetabularia
Acetabularia, genus of single-celled green algae (family Polyphysaceae) found in subtropical seas. The algae are......
achondroplasia
achondroplasia, genetic disorder characterized by an abnormality in the conversion of cartilage into bone. As a......
acidosis
acidosis, abnormally high level of acidity, or low level of alkalinity, in the body fluids, including the blood.......
acorn
acorn, nut of the oak. Acorns are usually seated in or surrounded by a woody cupule. They mature within one to......
acquired character
acquired character, in biology, modification in structure or function acquired by an organism during its life,......
Acrasieae
Acrasieae, class name for cellular slime molds (division Myxomycophyta). The class contains a single order, Acrasiales,......
acrocephalosyndactyly
acrocephalosyndactyly, congenital malformation of the skeleton affecting the skull and limbs. The disorder most......
Actinomycete
Actinomycete, (order Actinomycetales), any member of a heterogeneous group of gram-positive, generally anaerobic......
actinomyxidian
actinomyxidian, any parasitic microorganism of the class Actinomyxidia (Actinosporea), phylum Myxosporidia (Myxospora).......
action potential
action potential, the brief (about one-thousandth of a second) reversal of electric polarization of the membrane......
adaptation
adaptation, in biology, the process by which a species becomes fitted to its environment; it is the result of natural......
adaptive radiation
adaptive radiation, evolution of an animal or plant group into a wide variety of types adapted to specialized modes......
addiction
addiction, physical or psychological need for a substance or behavior that is physically, psychologically, or socially......
adductor muscle
adductor muscle, any of the muscles that draw a part of the body toward its median line or toward the axis of an......
adenovirus
adenovirus, any virus belonging to the family Adenoviridae. This group of viruses was discovered in the 1950s and......
adenovirus infection
adenovirus infection, any of a group of illnesses caused by infection with an adenovirus. There are numerous different......
adipose cell
adipose cell, connective-tissue cell specialized to synthesize and contain large globules of fat. There are two......
adipose tissue
adipose tissue, connective tissue consisting mainly of fat cells (adipose cells, or adipocytes), specialized to......
adjustment
adjustment, in psychology, the behavioral process by which humans and other animals maintain an equilibrium among......
adolescence
adolescence, transitional phase of growth and development between childhood and adulthood. The World Health Organization......
adrenal gland
adrenal gland, either of two small triangular endocrine glands one of which is located above each kidney. In humans......
adulthood
adulthood, the period in the human lifespan in which full physical and intellectual maturity have been attained.......
aecium
aecium, a cluster-cup or fruiting body of certain rust fungi (phylum Basidiomycota, kingdom Fungi). Yellow to orange......
Aerobe
Aerobe, an organism able to live and reproduce only in the presence of free oxygen (e.g., certain bacteria and......
affective disorder
affective disorder, mental disorder characterized by dramatic changes or extremes of mood. Affective disorders......
African horse sickness
African horse sickness (AHS), disease of Equidae (horses, mules, donkeys, and zebras) caused by an orbivirus called......
African swine fever
African swine fever (ASF), highly contagious and usually fatal viral disease of swine that is characterized by......
Agaricales
Agaricales, order of fungi in the class Agaricomycetes (phylum Basidiomycota, kingdom Fungi). One of the most diverse......
agenesis
agenesis, in human physiology, failure of all or part of an organ to develop during embryonic growth. Many forms......
aging
aging, progressive physiological changes in an organism that lead to senescence, or a decline of biological functions......
agnosia
agnosia, loss or diminution of the ability to recognize objects, sounds, smells, tastes, or other sensory stimuli.......
agrostology
agrostology, the branch of botany concerned with the study of grasses, especially their classification. In 1708......
AIDS
AIDS, infectious disease caused by human immunodeficiency virus (HIV). HIV is a lentivirus (literally meaning “slow......
Air sac
Air sac, any of the air-filled extensions of the breathing apparatus of many animals. Air sacs are found as tiny......
albinism
albinism, (from the Latin albus, meaning “white”), hereditary condition characterized by the absence of pigment......
Algae
Algae, members of a group of predominantly aquatic photosynthetic organisms of the kingdom Protista. Algae have......
- Introduction
- Photosynthesis, Diversity, Ecology
- Photosynthesis, Aquatic Ecosystems, Biomass
- Toxicity, Pollution, Nutrients
- Photosynthesis, Diversity, Nutrition
- Flagella, Photosynthesis, Microscopy
- Photosynthesis, Pigments, Light
- Nutrient Storage, Photosynthesis, Autotrophs
- Reproduction, Life Cycles, Adaptations
- Evolution, Paleontology, Photosynthesis
- Phycology, Photosynthesis, Taxonomy
alkalosis
alkalosis, abnormally low level of acidity, or high level of alkalinity, in the body fluids, including the blood.......
allergen
allergen, substance that in some persons induces the hypersensitive state of allergy and stimulates the formation......
allergy
allergy, hypersensitivity reaction by the body to foreign substances (antigens) that in similar amounts and circumstances......
Alternation of generations
Alternation of generations, in biology, the alternation of a sexual phase and an asexual phase in the life cycle......
Alzheimer disease
Alzheimer disease, degenerative brain disorder that develops in mid-to-late adulthood. It results in a progressive......
amblyopia
amblyopia, reduction in vision in one or both eyes due to abnormal visual experience in early childhood, leading......
American Philosophical Society
American Philosophical Society, oldest extant learned society in the United States, founded under the impetus of......
amphibian chytridiomycosis
amphibian chytridiomycosis, a disease affecting amphibians, especially frogs, caused by the fungus Batrachochytrium......
amygdala
amygdala, region of the brain primarily associated with emotional processes. The name amygdala is derived from......
amyloidosis
amyloidosis, disease characterized by the deposition of an abnormal protein called amyloid in the connective tissues......
amyotrophic lateral sclerosis
amyotrophic lateral sclerosis (ALS), progressive neurodegenerative condition characterized by the gradual loss......
Anabaena
Anabaena, genus of nitrogen-fixing blue-green algae with beadlike or barrel-like cells and interspersed enlarged......
Anabolism
Anabolism, the sequences of enzyme-catalyzed reactions by which relatively complex molecules are formed in living......
anaerobic digestion
anaerobic digestion, chemical process in which organic matter is broken down by microorganisms in the absence of......
anal canal
anal canal, the terminal portion of the digestive tract, distinguished from the rectum because of the transition......
analogy
analogy, in biology, similarity of function and superficial resemblance of structures that have different origins.......
anaphase
anaphase, in mitosis and meiosis, the stage of cell division in which separated chromatids (or homologous [like]......
Anatomy
Anatomy, a field in the biological sciences concerned with the identification and description of the body structures......
Androgen
Androgen, any of a group of hormones that primarily influence the growth and development of the male reproductive......
aneurysm
aneurysm, widening of an artery that develops from a weakness or destruction of the medial layer of the blood vessel.......
Angelman syndrome
Angelman syndrome, rare genetic disorder that affects the nervous system. The syndrome is named for English physician......
angina pectoris
angina pectoris, pain or discomfort in the chest, usually caused by the inability of diseased coronary arteries......
angioedema
angioedema, allergic disorder in which large, localized, painless swellings similar to hives appear under the skin.......
Animal development
Animal development, the processes that lead eventually to the formation of a new animal starting from cells derived......
- Introduction
- Embryogenesis, Morphogenesis, Differentiation
- Embryo Formation, Cell Differentiation, Morphogenesis
- Amphioxus, Echinoderms, Amphibians
- Reptiles, Birds, Mammals
- Adaptations, Mammals, Embryology
- Embryonic Induction, Cell Signaling, Morphogenesis
- Organogenesis, Histogenesis
- Sense Organs, Embryology, Evolution
- Mesoderm, Embryo, Morphogenesis
- Excretion, Organs, Embryology
- Reproduction, Embryology, Gametes
- Pharynx, Outgrowths, Embryology
- Larval, Metamorphosis, Growth
- Metamorphosis, Hormones, Morphogenesis
- Direct, Embryonic, Larval
animal disease
animal disease, an impairment of the normal state of an animal that interrupts or modifies its vital functions.......
Animal testing
Animal testing, the use of nonhuman animals in scientific and medical experiments. Animal testing has been a crucial......
Animals That Were Named Totally Wrong
The colloquial names given to many animals can be confusing because they suggest something that is not the case.......
ankle
ankle, in humans, hinge-type, freely moving synovial joint between the foot and leg. The ankle contains seven tarsal......
Annual
Annual, any plant that completes its life cycle in a single growing season. The term is usually applied to herbaceous......
anorexia
anorexia, persistent lack of appetite not caused by repletion. It may spring from psychoneurotic causes, as in......
Anthracnose
Anthracnose, a group of fungal diseases that affect a variety of plants in warm, humid areas. Shade trees such......
anthrax
anthrax, acute, infectious, febrile disease of animals and humans caused by Bacillus anthracis, a bacterium that......
Anthrozoology
Anthrozoology, study of the interactions and relationships between human and nonhuman animals. Anthrozoology spans......
antibiotic resistance
antibiotic resistance, loss of susceptibility of bacteria to the killing (bacteriocidal) or growth-inhibiting (bacteriostatic)......
antibody
antibody, a protective protein produced by the immune system in response to the presence of a foreign substance,......
antigen
antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which......
antigenic drift
antigenic drift, random genetic mutation of an infectious agent resulting in minor changes in proteins called antigens,......
antigenic shift
antigenic shift, genetic alteration occurring in an infectious agent that causes a dramatic change in a protein......
antitoxin
antitoxin, antibody, formed in the body by the introduction of a bacterial poison, or toxin, and capable of neutralizing......
anxiety disorder
anxiety disorder, any of several disorders that are characterized by a feeling of fear, dread, or apprehension......