ASVAB General Science Practice Test 147189

Questions 5
Topics Ecosystem, Endoskeleton, Prefixes, Tertiary Consumers, Veins

Study Guide

Ecosystem

An ecosystem is a biological community of interacting organisms and their physical environment. This includes both the biotic (living) and abiotic (non-living).

Endoskeleton

An endoskeleton (internal skeleton) is a charateristic of vertebrate animals, including humans.

Prefixes

A prefix is added to the base units of the metric system to indicate variations in size. Each prefix specifies a value relative to the base unit in a multiple of 10. Common prefixes are:

Prefix Symbol Relative Value Example
mega M 106 (1,000,000) Mm
kilo k 103 (1,000) km
base unit N/A 1 m
centi c 10-2 (1/100) cm
milli m 10-3 (1/1,000) mm
Tertiary Consumers

Tertiary consumers eat primary consumers and secondary consumers and are typically carnivorous predators. Tertiary consumers may also be omnivores. Examples include wolves, sharks, and human beings.

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.