ASVAB General Science Practice Test 344500

Questions 5
Topics Atomic Number, Decomposers, Genes, Outer Planets, Thermosphere

Study Guide

Atomic Number

The Periodic Table of the Elements categorizes elements primarily by the number of protons in their nucleus (atomic number) and secondarily by the characteristics they exhibit.

Decomposers

Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.

Genes

The gene is the base unit of inheritance and is contained within DNA. A gene may come in several varieties (alleles) and there are a pair of alleles for every gene. If the alleles are alike, a person is homozygous for that gene. If the alleles are different, heterozygous.

Outer Planets

In contrast to the solid terrestrial planets, the outer planets (Jupiter, Saturn, Uranus, and Neptune) consist of hydrogen and helium gas and water.

Thermosphere

Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.