Biology Quiz 7

The colour of the eye depends upon the amount and quality of melanin present in the iris. A high concentration of melanin gives the iris a brown colour, a moderate concentration of melanin results in a greenish or hazel iris, and a low concentration of melanin results in a blue iris.

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

Black Death was a devastating global epidemic of bubonic plague that struck Europe and Asia in the mid-1300s.

Charles Darwin (1809-1882) and Alfred Russel Wallace (1823-1913) were contemporary naturalists who proposed a similar theory of organic evolution. Wallace greatly admired On the Origin of Species. In turn, Darwin regarded Wallace as the one man who truly understood the idea of evolution by natural selection.

Sporozoite is the infective stage of the Malarial Parasite. Malaria infection begins when an infected female Anopheles mosquito bites a person, injecting Plasmodium parasites, in the form of sporozoites, into the bloodstream. The sporozoites pass quickly into the human liver. The sporozoites multiply in the liver cells, causing no symptoms.

The age of a tree can be determined by counting the rings from the pith of the trunk to the bark. Tree rings are the most accurate indicator of a tree's age. Finding the age of a tree by counting annual growth rings is called dendrochronology.

Amphibians can endure certain measures of mixing of oxygenated and deoxygenated blood since they don't need a lot of energy.

Bullets contain lead, and once in the body, it can cause lead poisoning. Most pistol bullets are made of a lead-antimony alloy encased in a soft brass or copper-plated soft steel jacket. In rifle and machine-gun bullets, a soft core of lead is encased in a harder jacket of steel or cupronickel.

The main function of white blood cells (WBCs) in the body is to protect the body against disease. WBCs protect the body against infection. As WBCs travel through the bloodstream and tissues, they locate the site of an infection and act as an army general to notify other WBCs of their location to help defend the body from an attack of an unknown organism.

The rock dove, rock pigeon, or common pigeon is a member of the bird family Columba-livia (doves and pigeons).