ASVAB General Science Practice Test 653378

Questions 5
Topics Consumers, Medulla, Spinal Cord, Types of Rock, Veins

Study Guide

Consumers

Most animals consume other organisms to survive. Consumers (heterotrophs) are divided into three types, primary, secondary, and tertiary, based on their place in the food chain.

Medulla

Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.

Spinal Cord

The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.

Types of Rock

The Earth's rocks fall into three categories based on how they're formed. Igneous rock (granite, basalt, obsidian) is formed from the hardening of molten rock (lava), sedimentary rock (shale, sandstone, coal) is formed by the gradual despositing and cementing of rock and other debris, and metamorphic rock (marble, slate, quartzite) which is formed when existing rock is altered though pressure, temperature, or chemical processes.

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.