Biology Quiz 7

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.

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.

The human-infective stage of malaria is sporozoites from the salivary gland of an infected mosquito. The sporozoites grow and multiply in the liver to become merozoites.

The starfish has respiratory organ but does not have brain. They have a complex nervous system that allows them to make a decision. This nervous system is centralized in the ring around the mouth.

Outside the nucleus, DNA is found in Mitochondria. Most DNA is located in the cell nucleus (where it is called nucleus DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA).

Tissue culture is a technique in which a small fragments of a plant (explant) are introduced into an artificial, nutrient medium, which allows its functioning or growth. Fragments of plant material, perhaps even just a couple of cells, are placed in an artificial growing medium to develop into new plants.

Leukocytes are the blood corpuscles that help to build up resistance against diseases. White blood cells (WBCs), also known as leukocytes, are responsible for protecting the body from infection. As part of the immune system, WBCs circulate in the blood and respond to injury or illness.

DPT is a combination vaccine to protect against Diphtheria, Tetanus and Pertussis (whooping cough).

The approximate time required for a heartbeat is 0.8 second. A normal resting heart rate for adults ranges from 60 to 100 (for children- 70 to 100) beats per minute. (Approximate time required for a heartbeat = 60 second ÷ average heart rate ≈ 0.8 second).

The vector of disease sleeping sickness is tsetse fly. Sleeping sickness (African Trypanosomiasis) is caused by microscopic parasites of the species Trypanosoma brucei. It is transmitted by the tsetse fly (Glossina species).