What is a gene?
A gene is a stretch of DNA that carries the instructions for building a protein or RNA molecule. Genes are the basic units of heredity — they pass traits from parents to offspring.
Just know.
25 facts — science, space, the body, the world. No fluff.What is DNA?
DNA (deoxyribonucleic acid) is the molecule that stores the genetic instructions for all known living things. Its double-helix shape was confirmed in 1953 by Watson, Crick, Franklin and Wilkins.
What is CRISPR?
CRISPR is a gene-editing tool adapted from a bacterial immune system. It lets scientists cut and rewrite DNA at precise spots, and won the 2020 Nobel Prize in Chemistry.
What is a virus?
A virus is a tiny package of genetic material inside a protein shell. It is not fully alive — it can only reproduce by hijacking the cells of a host organism.
What is an antibiotic?
An antibiotic is a drug that kills bacteria or stops them from growing. Antibiotics do nothing against viruses, which is why they are not prescribed for colds or flu.
How does a vaccine work?
A vaccine trains your immune system to recognise a pathogen by showing it a harmless version or fragment of it. If the real pathogen shows up later, your body already knows how to fight it.
What is evolution?
Evolution is the change in the inherited traits of a population over generations, driven mainly by mutation and natural selection. Charles Darwin articulated the modern theory in 1859.
What is photosynthesis?
Photosynthesis is how plants, algae and some bacteria turn sunlight, water and carbon dioxide into sugar and oxygen. Nearly all the oxygen you breathe comes from it.
What is the periodic table?
The periodic table arranges all 118 known chemical elements by the number of protons in their atoms. Elements in the same column behave in chemically similar ways.
What is an atom?
An atom is the smallest unit of ordinary matter that keeps an element's identity: a nucleus of protons and neutrons with electrons around it. Everything you can touch is built from atoms.
What is a molecule?
A molecule is two or more atoms bonded together — like O2 (two oxygens) or H2O (two hydrogens and an oxygen). Molecules are the building blocks of compounds.
What is e?
The number e (about 2.71828) is the base of natural growth — the amount continuously compounding interest approaches. It shows up wherever things grow or decay smoothly.
What is pi?
Pi (about 3.14159) is the ratio of any circle's circumference to its diameter. It never repeats or ends, no matter how many digits you compute.
What is gravity?
Gravity is the attraction between anything with mass or energy. Einstein described it not as a force but as the bending of space and time itself.
What is electricity?
Electricity is the flow of electric charge — usually electrons moving through a wire. It powers everything from your brain's signals to city grids.
What is a black hole?
A black hole is a region where gravity is so strong that nothing — not even light — can escape past its event horizon. The first direct image of one was released in 2019.
What is a supernova?
A supernova is the explosive death of a massive star, briefly outshining entire galaxies. It forges heavy elements like gold and scatters them across space.
What is quantum entanglement?
Entangled particles share a single quantum state, so measuring one instantly constrains the other — no matter the distance. Einstein nicknamed it "spooky action at a distance".
How fast is light?
Light travels at exactly 299,792,458 metres per second in a vacuum — the universal speed limit. Sunlight takes about 8 minutes 20 seconds to reach Earth.
What is climate change?
Climate change is the long-term shift in Earth's temperature and weather patterns, driven since the industrial era by greenhouse gases from burning fossil fuels.
What is a carbon footprint?
A carbon footprint is the total greenhouse gas emitted by a person, product or organisation, measured in CO2-equivalent tonnes. Everything you buy carries one.
What is renewable energy?
Renewable energy comes from sources that refill themselves — sunlight, wind, water, geothermal heat and biomass. Solar and wind are now the cheapest new power in most of the world.
What is an ecosystem?
An ecosystem is a community of living things plus the non-living world they interact with — a pond, a forest, a coral reef. Change one part and the whole web feels it.
What is DNA fingerprinting?
DNA fingerprinting identifies individuals from their unique genetic code. It has solved crimes, exonerated the innocent and settled paternity cases since the 1980s.
Why is the sky blue?
Air molecules scatter short blue wavelengths of sunlight in all directions much more strongly than red ones. At sunset the light path is longer, so blues scatter away and reds dominate.