ASVAB General Science Practice Test 669517

Questions 5
Topics DNA, Light Waves, Mesosphere, Primary Consumers, Veins

Study Guide

DNA

Deoxyribonucleic acid (DNA) is the molecule that contains genetic information. DNA is encoded through a combination of nucleotides that bind together in a specific double helix pattern.

Light Waves

Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.

Mesosphere

In the mesosphere, temperature again drops as altitude increases until the coldest point in the Earth's atmosphere, the mesopause, is reached where temperatures fall to −225 °F (−143 °C).

Primary Consumers

Primary consumers (herbivores) subsist on producers like plants and fungus. Examples are grasshoppers, cows, and plankton.

Veins

Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.