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Introduction to cell theory--the idea that 1) all living things are made of one or more cells, 2) cells are the basic unit of life and 3) all cells come from other cells. Explore the roles that Hooke, Leeuwenhoek and others played in developing cell theory.

Hooke and Leeuwenhoek were two of the first scientists to use microscopes to study the microscopic world of cells. Hooke coined the term "cell" after observing the tiny compartments in cork, while Leeuwenhoek discovered a variety of living creatures in pond water, blood, and other samples. They contributed to the cell theory by suggesting that cells are the fundamental units of life and structure, and that all living things consist of one or more cells that originate from other cells by division. 

All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular).

• Explain basic electricity relationships in series and parallel circuits.
• Use an ammeter and voltmeter to take readings in circuits.
• Provide reasoning to explain the measurements and relationships in circuits.
• Build circuits from schematic drawings.
• Determine if common objects are conductors or insulators.
• Compare and contrast AC and DC circuits.
• Describe how capacitors and inductors behave in a circuit.
• Experimentally determine the RC time constant.
• Construct RLC circuits and determine the conditions for resonance.

This podcast (audio) file explains how electric current can be obtained from the sun through the solar panel using direct illumination of the sun rays

Introduction to the cell.

• Predict how current will change when resistance of the circuit is fixed and voltage is varied.
• Predict how current will change when voltage of the circuit is fixed and resistance is varied.

Electrical devices convert the electrical energy carried by the charges into other types of energy such as heat, sound, and motion. Components in the appliance resist the flow of charge and are referred to as resistors. In this unit1 you will understand what resistance is, the factors that affect the resistance and the relationship between resistance and current.

Most of us use electricity every day in many different ways so it is important that we understand the dangers, or hazards, associated with electricity and we know how to use it safely.

Even though molecules, proteins, viruses, and cells are all tiny, there are significant size differences between them. The diameter of a water molecule is roughly 0.28 nanometers. The diameter of the protein hemoglobin is roughly 5 nanometers. The diameter of the HIV virus is roughly 120 nanometers. A red blood cell is 6-8 micrometers.

When a circuit is connected and complete, charge can move through the circuit. Charge will not move unless there is a reason, a force to drive it around the circuit. Think of it as though charge is at rest and some- thing has to push it along. This means that work needs to be done to make charge move. A force acts on the charges, doing work, to make them move. The force is provided by the battery in the circuit.