[Free Registration/Login may be required to access all resource tools.] This site explains Rutherford's discovery of the nucleus and the planetary model of the atom and the role of gold foil experiment in refining the atomic model. It...

[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...

[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...

[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...

[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...

[Free Registration/Login may be required to access all resource tools.] The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome how to create a specific...

Students will find an explanation of the neutron particle located inside the atom's nucleus. Website also defines isotopes and the process of radioactive decay.

The website provides an explanation of the electrons' position in their orbitals as they spin around the nucleus. Quantum theory is also explored by explaining that the exact location of a specific electron is a not exact but a guess.

Explore the convept that DNA and proteins are key molecules of the cell nucleus.

Bacteria are single celled microbes. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Instead their control centre containing the genetic information is contained in a single...

This lesson focuses on the structure of atoms. All substances are made from atoms. Each atom is made of a nucleus - containing protons and neutrons - surrounded by electrons. It provides a link to an assessment.

The number of protons in the atom of an element determines its place in the Periodic Table. The number of electrons in an atom is the same as the number of protons. These electrons are arranged in shells or 'energy levels' around the...

[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...

Explains what the effective nuclear charge is and how electrons can create a shield between a nucleus and an outer electron. Presents exercises for comparing orbital sizes with effective nuclear charges. Requires Java.

X-rays, gamma rays and beta particles are all used in medicine to treat internal organs. X-rays are produced by firing electrons at a metal target and gamma rays are emitted by the nucleus of radioactive atoms. Gamma rays are used to...

Observe the probable location of electrons around an atom. Trace the electrons over time to draw conclusions about where electrons are likely to be found around an atom's nucleus. How does the trace pattern relate to the electron cloud...

Activity 3 of this module investigates: How do we know what's inside an atom? From Ernest Rutherford's Gold Foil Experiment to his investigation of the Plum Pudding model, students become aware of the Nuclear Model of an Atom. Also in...

This resource provides a detailed diagram of animal, bacterial and plant cells and viral structure. Also included are detailed drawings, with definitions, of each of the cellular organelles.

This site offers a wealth of online textbook-related materials that encourage the discovery of science in the world around us. Enter the site to access material on specific topics. Each section contains reading material (complete with...

This study resource from Khan Academy provides practice questions for the MCAT. "Cell theory" questions are provided on this resource.

From The Mad Scientist Network web site. Using a question and answer format, this page discusses three types of nuclear reactions - spontaneous decay reactions, nuclear fision reactions, and nuclear fusion reactions. Each reaction type...

From the Mad Scientist Network web site. Using a question and answer format, this page describes the various types of fusion processes and the physical requirements needed for their initiation and sustenance. Factors affecting the rates...

From the Mad Scientist Network web site. Using a question and answer format, this page explains the differences between nuclear fusion and nuclear fission. The details of each process are sketched in simple language.

This tutorial compares prokaryotic and eukaryotic cellular organization and contrasts cells with viruses. Includes a practice quiz to test your knowledge.