CK-12 Foundation
Ck 12: Life Science: Prokaryotic and Eukaryotic Cells
[Free Registration/Login may be required to access all resource tools.] There are two basic types of cells, prokaryotic cells and eukaryotic cells. The main difference between eukaryotic and prokaryotic cells is that eukaryotic cells...
BiologyWise
Biology Wise: Plant Cell Organelles
Explains how plant and animal cells are different and describes the organelles in a plant cell.
BiologyWise
Biology Wise: Nuclear Membrane Function
Describes the structure and functions of the membrane surrounding a cell nucleus.
BiologyWise
Biology Wise: What Is the Nucleolus?
The characteristics, structure, and functions of the nucleolus are described.
University of Arizona
Prokaryotes, Eukaryotes, & Viruses
This tutorial compares prokaryotic and eukaryotic cellular organization and contrasts cells with viruses. Includes a practice quiz to test your knowledge.
CK-12 Foundation
Ck 12: Endosymbiosis the Evolution of Eukaryotes
[Free Registration/Login may be required to access all resource tools.] Learn about the evolution of eukaryotes which is explained by the endosymbiotic theory.
CK-12 Foundation
Ck 12: Life Science: Archaea
[Free Registration/Login may be required to access all resource tools.] For many years, archaea were classified as bacteria. Like the bacteria, archaea lacked a nucleus and membrane-bound organelles and, therefore, were prokaryotic...
CK-12 Foundation
Ck 12: Life Science: Mitosis and Cytokinesis
[Free Registration/Login may be required to access all resource tools.] During mitosis, the DNA in a nucleus must replicate. The copied DNA is divided into two genetically identical sets, so that after cytokinesis or cell division, each...
Wikimedia
Wikipedia: Cytoplasm
Wikipedia offers brief but accurate information on cytoplasm, the matter contained within the plasma membrane of a cell.
CK-12 Foundation
Ck 12: Life Science: Protist Characteristics
[Free Registration/Login may be required to access all resource tools.] Protists are eukaryotes, which means their cells have a nucleus and other membrane-bound organelles. Most protists are single-celled. Other than these features, they...
CK-12 Foundation
Ck 12: Life Science: Domains of Life
[Free Registration/Login may be required to access all resource tools.] Humans are in the same domain as trees and algae. What could they possibly have in common? It is the location of their DNA inside their cells. Their cells all have a...