ASVAB General Science Practice Test 498455

Questions 5
Topics Biosphere, Carbohydrates, Cell Division, Crust, Terrestrial Planets

Study Guide

Biosphere

The biosphere is the global ecological system integrating all living beings and their relationships. This includes their interactions with the lithosphere (the rigid outer part of the earth, consisting of the crust and upper mantle), hydrosphere (all surface water), and atmosphere (the envelope of gases surrounding the planet).

Carbohydrates

Carbohydrates are major sources of energy for the body and are found in sugars (fruit, cane sugar, beets) and starches (bread, rice, potatoes, pasta).

Cell Division

Cell division is the process by which cells replicate genetic material in the nucleus. Cell division consists of several phases:

Phase Major Process
interphase chromosomes replicate into chromatids and the cell grows
prophase chromatids pair up
metaphase paired chromatids move to opposite sides of the cell
anaphase cell elongates and nucleus begins to separate
telophase separation of nucleus is complete resulting in two new nuclei
cytokinesis cytoplasm and cell membranes complete their separation resulting in two separate cells
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.

Terrestrial Planets

The four planets closest to the Sun (Mercury, Venus, Earth, and Mars) are called terrestrial (Earth-like) planets because, like the Earth, they're solid with inner metal cores covered by rocky surfaces.