Biology Online Quiz

Yawning occurs when CO₂ concentration in the blood is high, and Oxygen (O₂) concentration is low. The yawn acts as a boost to the O₂ levels.

A polymer is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. polyethylene (alse known as Polythene) is a light, versatile synthetic resin made from the polymerization of ethylene.

Among the given options, Mollusc plasma bears the smallest living cell. Mycoplasma is the smallest living known cell. It is prokaryotic, devoid of a cell wall and can live without oxygen. It is pathogenic to both plants and animals.

Dinosaurs went extinct about 65 million years ago (at the end of the Cretaceous Period), after living on Earth for about 165 million years.

Melanin is a type of pigment that gives colour to the hair, skin, and eyes in humans and animals. It is a complex polymer derived from the amino acid tyrosine.

Arboreal animals are those animals that spend most of their life on trees. Examples of such animals include chameleons, lizards, green tree pythons, tree snails, koalas, squirrels, cats, monkeys, parrots, etc.

Men and women have an equal number of bones which is 206. A baby's body has about 300 bones at birth. These eventually fuse (grow together) to form the 206 bones that adults have.

Genetically modified (GM) foods are foods derived from organisms whose genetic material (DNA) has been modified in a way that does not occur naturally. GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells.

Ostrich is the largest living bird on the planet. With its long neck and brown plumage, the ostrich is the tallest and heaviest bird. An adult ostrich weighs up to 150 kilograms and has a maximum height of 6 feet.

A Roundworm (called Ascaris lumbricoides) is a human parasite found in the Small intestine. It infects a human's small intestine and acts as a parasite, getting nutrients from its host's intestinal tract.