ASVAB General Science Practice Test 363549

Questions 5
Topics Biosphere, Blood Types, Cell Division, DNA, Medulla

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).

Blood Types

Blood is categorized into four different types (A, B, AB, and O) based on the type of antigens found on the outside of the red blood cells. Additionally, each type can be negative or positive based on whether or not the cells have an antigen called the Rh factor.

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
DNA

Deoxyribonucleic acid (DNA) is the molecule that contains genetic information. DNA is encoded through a combination of nucleotides that bind together in a specific double helix pattern.

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.