Biology Quiz 8

Dehydration is caused by not drinking enough fluid or by losing more fluid than you take in. During dehydration, Sodium chloride is the substance that is usually lost by the body. Fluid is lost through sweat, tears, vomiting, urine or diarrhea. Dehydration is almost invariably associated with some loss of salt (sodium chloride) as well.

The huge muscles that power the wings attach to a flat part of the breastbone called the keel. Some flightless birds, including ostriches, do not have a keel.

Silverfish, Starfish and Cuttlefish are not true fish. Silverfish is not a fish but an insect. Starfish is not a fish. It do not have gills, scales, or fins. Cuttle fish is not the fish but is a Mollusc belonging to the class Cephalopoda. Dogfish are small, bottom-dwelling sharks.

Birds have only one functional ovary, typically on the left side of the body.

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.

By mass, about 96 percent of the human body is made up of just four elements: oxygen (65 percent), carbon (18.5 percent), hydrogen (9.5 percent), and nitrogen (3.3 percent). Oxygen (O) together with hydrogen form water, which is the primary solvent found in the body and is used to regulate temperature and osmotic pressure.

Hypothermia occurs in human beings. It occurs when the human body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6°F (37°C). Hypothermia occurs as temperature falls below 95°F (35°C).

The adult human brain weighs about 1200–1400 gm which is about 2% of the total body weight. The weight of an average human brain is about 1.36 kg.

Antigen stimulates the production of antibodies when introduced into a living organism. It is a substance that enters the body and starts a process that can cause disease. The body then usually produces substances (antibodies) to fight the antigens.

An antibiotic is a chemical synthesized by a micro-organism against another micro-organism. It is a medicine which is used for destroying bacteria and curing infections. The term antibiotic, coined in 1942, describes any substance produced by a microorganism, and subsequently by chemical synthesis, that is antagonistic to the growth of other microorganisms.