biology

Honey produced by bees is one of the few foods that does not spoil under normal storage conditions.

Mass extinction is a significant decrease in biodiversity over a geologically short period.

Insects make up over half of all known animal species, with approximately 1 million described species.

Spiders produce silk through specialized glands and use it for webs, egg sacs, and prey capture.

Lichens are composite organisms formed by a symbiosis between fungi and photosynthetic algae or cyanobacteria.

Ferns are vascular plants that reproduce via spores rather than seeds.

Mycorrhizae are mutualistic associations between fungi and plant roots that help plants absorb water and nutrients.

Glycolysis is the metabolic pathway that converts glucose into pyruvate, releasing energy in the form of ATP and NADH.

Induced pluripotent stem cells were first generated by Shinya Yamanaka in 2006, leading to the 2012 Nobel Prize in Physiology or Medicine.

Polymerase chain reaction, PCR, is a technique to amplify specific DNA segments, invented by Kary Mullis in 1983.

Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect them from degradation.

The mitochondrial DNA in humans is inherited almost exclusively from the mother.

Charles Darwin's voyage on HMS Beagle from 1831 to 1836 provided observations central to his theory of evolution.

The mitochondrial Eve is the most recent matrilineal common ancestor of all currently living humans, estimated to have lived around 150,000 years ago in Africa.

E. coli is a bacterium commonly found in the lower intestine of warm-blooded organisms; most strains are harmless.

Flowering plants, or angiosperms, are the most diverse group of land plants with about 300,000 species.

Conifers are gymnosperms that produce seeds in cones and include pines, spruces, firs, and cedars.

Coral spawn synchronously in mass annual events, releasing eggs and sperm into the water for external fertilization.

The Krebs cycle, also called the citric acid cycle, is a series of chemical reactions used by all aerobic organisms to release stored energy.

Stem cells include embryonic stem cells, which are pluripotent, and adult stem cells, which are typically multipotent.

Hemophilia is a hereditary bleeding disorder caused by deficiency of clotting factors, most commonly factor VIII.

Apoptosis is programmed cell death, a controlled process essential for development and tissue maintenance.

Genome editing with CRISPR-Cas9 uses guide RNAs to direct the Cas9 nuclease to specific DNA sequences for cleavage.

The lac operon in E. coli was the first genetic regulatory mechanism described, by Jacob and Monod in 1961.

Gregor Mendel discovered the laws of genetic inheritance through experiments with pea plants in the 1860s.

Mitochondria generate most of a cell's adenosine triphosphate (ATP) through oxidative phosphorylation.

Penicillin was discovered by Alexander Fleming in 1928 from the mold Penicillium notatum.

The human body contains approximately 37 trillion cells, according to a 2013 estimate.

There are four DNA nucleotide bases: adenine, thymine, guanine, and cytosine.

The cerebellum coordinates voluntary movement and is critical for motor learning.

Sleep is divided into rapid eye movement and non-rapid eye movement stages with distinct neurological characteristics.

Memory has multiple systems including sensory memory, short-term memory, working memory, and long-term memory.

Classical conditioning was first demonstrated by Ivan Pavlov in his experiments with dogs in the late 19th and early 20th centuries.

The liver performs over 500 functions including detoxification, protein synthesis, and bile production.

White blood cells, or leukocytes, are immune system cells that defend the body against infectious disease and foreign invaders.

The pancreas produces digestive enzymes and hormones including insulin and glucagon.

The thyroid gland produces hormones that regulate metabolism, growth, and development.

Osmosis is the diffusion of solvent molecules through a semipermeable membrane from lower to higher solute concentration.

Photosynthesis converts carbon dioxide and water into glucose and oxygen using light energy in chloroplasts.

Cellular respiration extracts energy from glucose by oxidation, producing ATP, carbon dioxide, and water.

Genes are sequences of DNA that contain instructions for making functional products such as proteins.

The human genome contains roughly 19,000 to 20,000 protein-coding genes.

Mitosis is cell division that produces two genetically identical daughter cells.

Charles Darwin published On the Origin of Species in 1859, presenting evolution by natural selection.

The human brain contains approximately 86 billion neurons.

The blood-brain barrier is a selective semipermeable border that regulates passage of substances from circulation into the central nervous system.

Adult human bones number 206 in a typical skeleton.

Fungi form their own kingdom of life and include molds, yeasts, and mushrooms.

Endosymbiotic theory proposes that mitochondria and chloroplasts originated as free-living bacteria engulfed by ancestral eukaryotic cells.

Dolly the sheep, the first mammal cloned from an adult somatic cell, was born on July 5, 1996.

African elephants are the largest land animals, with adult males weighing up to about 6,000 kilograms.

Bees are essential pollinators that support the reproduction of many flowering plants worldwide.

Coral reefs are diverse marine ecosystems built by colonies of tiny animals called coral polyps.

Tardigrades, also known as water bears, can survive extreme conditions including the vacuum of space.

Penguins are flightless birds that live almost exclusively in the Southern Hemisphere.

Spiders are arachnids and not insects, having eight legs rather than six.

Sharks have skeletons made of cartilage rather than bone.

Migration is a seasonal movement of animals from one region to another, often spanning thousands of kilometers.

Marie Curie was the first woman to win a Nobel Prize, sharing the 1903 Physics Prize with her husband Pierre and Henri Becquerel.

Polar bears are native to the Arctic Circle and are classified as marine mammals.

Most gorillas are critically endangered, with mountain gorilla populations slowly recovering due to conservation efforts.

Bald eagles, the U.S. national bird, were removed from the U.S. endangered species list in 2007.

Mosquitoes are responsible for the most human deaths of any animal worldwide, primarily through disease transmission.

Rosalind Franklin's X-ray diffraction images were critical to the discovery of the structure of DNA.

RNA stands for ribonucleic acid and plays roles in the coding, decoding, regulation, and expression of genes.

Enzymes are biological catalysts, typically proteins, that speed up chemical reactions in cells.

Stem cells are undifferentiated cells with the ability to develop into specialized cell types.

The mitochondrion is often called the powerhouse of the cell because it generates most of the cell's ATP.

The cell is the basic structural and functional unit of all known living organisms.

Human DNA contains approximately 3.2 billion base pairs distributed across 23 pairs of chromosomes.

The human heart beats roughly 100,000 times per day on average.

DNA's double-helix structure was described by James Watson and Francis Crick in 1953, building on data from Rosalind Franklin and Maurice Wilkins.

CRISPR-Cas9 gene editing was awarded the 2020 Nobel Prize in Chemistry to Jennifer Doudna and Emmanuelle Charpentier.

The hippocampus plays a central role in the formation of new long-term memories.

Dopamine is a neurotransmitter involved in reward, motivation, motor control, and other brain functions.

Serotonin is a neurotransmitter implicated in mood regulation, appetite, and sleep.

The prefrontal cortex is associated with executive functions including planning, decision-making, and self-control.

The kidneys filter blood and produce urine, with adult human kidneys filtering about 180 liters of fluid per day.

Red blood cells lack a nucleus in mature form and circulate in human blood for approximately 120 days before being recycled.

Hormones are chemical messengers secreted by endocrine glands that regulate physiological processes.

Adrenaline, also called epinephrine, is a hormone and neurotransmitter that mediates the fight-or-flight response.

Lymph is a fluid that circulates through the lymphatic system, returning interstitial fluid to the bloodstream and aiding immunity.

Ribosomes are cellular structures responsible for synthesizing proteins by translating messenger RNA.

Messenger RNA carries protein-coding information from DNA to ribosomes for translation.

Meiosis is a specialized cell division that produces gametes with half the chromosome number.

Mendel's laws of inheritance, first published in 1866, form the basis of classical genetics.

There are five generally recognized senses in humans: sight, hearing, touch, taste, and smell.

Action potentials are rapid changes in voltage across a neuron's membrane that propagate along the axon.

Neurotransmitters are chemicals that transmit signals across synapses between neurons.

Hemoglobin is the iron-containing protein in red blood cells that transports oxygen.

Skin is the largest organ of the human body by surface area and weight.

Bacteria are single-celled prokaryotic organisms found in nearly every environment on Earth.

Viruses are infectious agents that replicate only inside the living cells of a host organism.

Photosynthetic cyanobacteria are believed to have produced the oxygen that accumulated in Earth's atmosphere starting about 2.4 billion years ago.

Insulin was first isolated and purified for clinical use by Banting, Best, Macleod, and Collip in 1921 to 1922.

The Human Genome Project produced its first essentially complete reference sequence in 2003.

Blue whales are the largest animals ever known to have lived, reaching lengths over 30 meters.

Cheetahs are the fastest land animals, capable of running up to about 110 kilometers per hour in short bursts.

Peregrine falcons are the fastest birds, reaching dive speeds over 350 kilometers per hour.

The giant sequoia is among the largest trees by volume, native to California's Sierra Nevada.