Scientists Say
A weekly word defined, in a sentence and in context. Click here to find the alphabetized list.
- Genetics
Scientists Say: Chromosome
This threadlike structure is made of DNA wrapped around protein. It allows the 3 billion base pairs in human DNA to stay neatly packaged in a cell.
- Earth
Scientists Say: Continent
A continent is a large land mass. Geologists recognize six of them — Africa, Antarctica, Eurasia, Australia, North America and South America.
- Life
Scientists Say: Mitochondrion
Mitochondria are structures inside cells that converts certain chemicals into adenosine triphosphate — a molecule cells use as energy.
- Space
Scientists Say: Supernova
When a star has too much mass, it can explode. The explosion is called a supernova.
- Brain
Scientists Say: Hippocampus
The hippocampus is an area of the brain that is essential for forming new memories.
- Chemistry
Scientists Say: Isotope
An isotope is a variety of an element that has the same number of protons but a different number of neutrons — or neutrally charged particles.
- Planets
Scientists Say: Eclipse
How the sun, moon and Earth line up determines whether there’s a solar or lunar eclipse.
- Chemistry
Scientists Say: Atomic number
How do you know where an element sits in the periodic table? Count its protons to get its atomic number.
- Plants
Scientists Say: Guttation
When water vapor can’t escape a plant, it might force its way out through a process called guttation.
- Plants
Scientists Say: Stomata
Plants have pores they open and close to let oxygen, carbon dioxide and water vapor in and out. These pores are called stomata.
- Brain
Scientists Say: Synapse
When brain cells need to pass messages, they do it without touching, across a space called a synapse.
- Planets
Scientists Say: Dwarf planet
Dwarf planets are distinct from the full-size models. A little too small, they also have a lot of space stuff filling their path around the sun.
