Scott Dutfield

Reference Mermaids — legendary half-human, half marine creatures — have fascinated people for centuries and inspired many "sightings."

Reference The sympathetic nervous system activates the "fight-or-flight" response, quickly readying the body to handle dangerous or stressful situations.

Reference Broadly speaking, biology is the study of life.

Reference Humans have invented six devices that combine to make work easier. These six simple machines are the wheel and axle, the lever, the inclined plane, the pulley, the screw and the wedge.

Reference The lymphatic system helps rid the body of toxins. Diseases of this system include lymphadenopathy, lymphoma and other disorders.

Reference Learn about the many differences between prokaryotic and eukaryotic cells and how they evolved.

Reference Learn all about the human body's many systems and some of its individual organs, both vital and vestigial.

Reference They're a popular feature of many gyms, and can help with overall fitness, but are exercise bikes good for losing weight?

REFERENCE Can running help to build muscle mass?

Reference Carbohydrates — one of the basic food groups — are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. They are important to a healthy diet.

Reference Thousands of years ago Britain was connected to mainland Europe, but during an ice age Brexit a tsunami tore them apart.

Reference They might look cute, but the toxins from a poison dart frog can be strong enough to kill several humans.

Reference The human heart is an organ that pumps blood throughout the body via the circulatory system.

Discover what separates alligators and crocodiles and how you can tell them apart.

They're not as famous as Darwin or Curie, but these heroes made our lives better through groundbreaking achievements.

Some of the world's strangest species can be found down under, from dolphin-tailed sea cows to mysterious marsupial moles.

The death of the dinosaurs was just one of five global events that saw millions of species wiped out. How do these events happen? And how can we stop it happening again?

Pigs are mammals with stocky bodies, flat snouts, small eyes and large ears. They are highly intelligent, social animals, and are found all over the world.