ASVAB General Science Practice Test 663779

Questions 5
Topics Atomic Number, Crust, Exoskeleton, Meiosis, Phase Transition

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.

Crust

The crust is the Earth's outermost layer and is divided into oceanic and continental types. Oceanic crust is 3 miles (5 km) to 6 miles (10 km) thick and is composed primarily of denser rock. Continental crust is 20 to 30 miles (30 to 50 km) thick and composed primarily of less dense rock. The crust makes up approximately one percent of the Earth's total volume.

Exoskeleton

An exoskeleton (external skeleton) is common in arthropods like insects, spiders, and crustaceans.

Meiosis

Reproductive (haploid) cells known as gametes have half as many (23) pairs of chromosomes as normal (diploid) cells. When the male gamete (sperm) combines with the female gamete (ovum) through meiosis to form a zygote, each gamete supplies half the chromosomes needed to form the normal diploid cells.

Phase Transition

A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.