Biologie
16 cards from across every topic, each citing a source. Tap one to open it in the feed.
- A jellyfish can turn itself back into a juvenile.
Turritopsis dohrnii is only about 4.5 millimetres across. When injured, starving or old, it rebuilds its cells and …
- An animal that simply regrows a lost leg.
The axolotl, a Mexican salamander, regenerates entire limbs, parts of its heart and even sections of its brain, without …
- An octopus has three hearts and blue blood.
Two hearts push blood through the gills; the third supplies the body. That body heart stops while the animal swims …
- Elephants carry 20 copies of a cancer-guard gene. You have one.
More cells, more divisions, more cancer, that is how it should go. Yet elephants with a hundred times your cell count …
- Every one of your cells houses former bacteria.
Mitochondria, the power plants of your cells, were free-living bacteria about two billion years ago. An ancestral cell …
- For every human there are 2.5 million ants.
A 2022 analysis estimates 20 quadrillion ants on Earth, a 2 followed by 16 zeros. Together they weigh in at around 12 …
- Fungi are closer relatives of yours than of plants.
Fungi and animals together form a group called Opisthokonta. Their last common ancestor lived after the plant lineage …
- How a bat catches a mosquito in pitch darkness.
The bat calls in ultrasound, depending on species between 11 and 212 kilohertz, well above your hearing. From the delay …
- How to soften rock-hard avocados in two days.
Bananas, apples, tomatoes and avocados keep ripening after harvest because they release the gas ethylene, a plant …
- No tree can grow taller than about 130 metres.
A tree does not pump water. Evaporation in the leaves draws it up from the roots as one continuous thread. With every …
- Sharks existed before trees did.
Sharks have been swimming the seas for around 400 million years. The first organism that counts as a tree …
- The strongest known biological material is snail teeth.
Limpets rasp algae off rock, and their tiny teeth take it: in 2015 researchers measured tensile strengths of 3.0 to 6.5 …
- The yellow in autumn leaves was there all summer.
Yellow and orange carotenoids sit in the leaf all year but are masked by green chlorophyll. In autumn the tree stops …
- Why giant movie ants would collapse on the spot.
Double a body's size and its surface area quadruples, but its volume and weight increase eightfold. Legs support weight …
- You have fewer genes than a rice plant.
Humans carry only about 20,000 protein-coding genes. Before the Human Genome Project, estimates ran to 100,000. Rice …
- You taste fizz with your 'sour' cells, not with the bubbles.
On the sour-sensing cells of your tongue sits an enzyme, carbonic anhydrase 4. It turns dissolved CO2 into carbonic …