Science

Batteries come in many different types. The most popular one is that of a dry cell. Dry cells are found in various devices such as toys, cameras, radios, and desktop computers. A multimeter is a...

Organelles are sub-compartments of the cells of certain eukaryotes and prokaryotes, each dedicated to its own specific function. It is thought that some, such as mitochondria, may have evolved...

Viruses are microbes that require host cells for proliferation. A virus enters a host cell and inserts its genome into the nuclear DNA. It uses the host's replication process to create its own...

Bone is a living, changing tissue that protects our organs and works with our musculature system to allow us to move. Bone also stores minerals and is responsible for making all of our red and...

Large and rectangular, a single 6-volt lantern battery actually consist of four cylindrical 1.5-volt batteries (aka "cells") wired in series within the plastic casing. To manufacture these...

Apoptosis is a type of deliberate cell suicide. It is a normal process used to prevent cancer and to cull defective cells from the body. It is in contrast to cell necrosis, in which cells die...

The cells of living organisms are of two basic types; prokaryotic and eukaryotic. The prokaryotic cell, the simpler type, is characteristic of organisms like bacteria and blue-green algae. The...

Bacteria are prokaryotic organisms composed of only one cell surrounded by a cell wall. This cell wall both protects the cell and gives it its shape. Studying the cell is one way to distinguish...

The nucleus can be made of a number of different things depending on its purpose. The atomic structure of elements contain nuclei, as do each cell within living things.

Foam structures consist of a solid material that is filled with voids, or bubbles. Foams are used for a variety of insulation and cushioning applications. Two of the primary categories of foam...

Cloning can either occur in nature with asexual reproduction, or with the careful administration of cell manipulation in science labs. Scientists employ several techniques to create an identical...

The two main types of nucleic acid are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). They store and convey the genetic code of a cell. Messenger RNA (mRNA) is built from a gene of DNA...

The process of DNA isolation and analysis uses a variety of techniques to identify genetic components. Developed over the course of the late 20th century, DNA testing can be used for a number of...

Many battery choices are available today for almost all applications. But the choices between wet cell and dry cell are limited. In most cases, portable devices do not have this option. The most...

Cell phones work by sending radio waves to a grid of radio towers set next to each other in a "cell" formation in a particular coverage area. Today, cell phone signals are digitized and sent on...

The three main structures of the cell are the membrane, the cytosol and its contents and the nucleus. The membrane is semi-permeable, allowing selected nutrients and signal molecules inside. The...

A pH meter utilizes voltage to measure the acidity or alkalinity of chemical substances. Most pH meters operate in a straightforward manner, with a digital screen that displays the pH value. Some...

Solids are divided into two categories: crystalline solids and amorphous solids. A crystalline solid has a long-range order that is rigid. Examples include table salt and ice. Amorphous solids...

Living cells are of two basic types---the prokaryotic cell and the eukaryotic cell. The prokaryotic cell is simpler in structure and occurs in such organisms as bacteria and blue-green algae. The...

The nucleus, being the nerve center of the cell, is the site of many intricate and essential chemical reactions. At the core of these are reactions involving DNA, the cell's genetic material....

Both ethanol (ethyl alcohol) and isopropanol (isopropyl alcohol) are alcohols that kill bacteria. Alcohols kill bacteria by first making the lipids that are part of the outer protective cell...

Amoebae are single-celled, crawling organisms often found in ponds. They have no definite shape and consist of flowing cytoplasm encased in a very flexible cell membrane. Amoebae have organelles...

A sperm cell is the male reproductive cell that carries the male portion of chromosomes, DNA or hereditary information to be fused with the female egg, or ovum. In humans and many other animal...

The hydrogen fuel cell splits hydrogen molecules away from water molecules through the process of electrolysis. The end result is hydrogen gas that can be used to charge batteries or as a fuel...

The cell membrane is the boundary between a living cell and its outside environment, and it is responsible for regulating what molecules pass into and out of the cell. Cell membranes can be...

The cell membrane, also called the plasma membrane or plasmalemma, regulates what enters and leaves the cell, and has many proteins embedded within it. Molecules cross the cell membrane by...

A male sperm cell must reach the egg cell (ovum) in the female and enter it. Shape and structure of the head portion of the sperm facilitates this action. A pointed tip in the head of the sperm...

The sticky female part in the center of the flower is called the stigma. A long tube called the style connects the stigma to the ovary, which contains a number of ovules, each of which contains...

Cells are of two basic types; the eukaryotic cell and the prokaryotic cell. The prokaryotic cell is typical of what are considered more primitive organisms like bacteria and blue-green algae....

The composition of a battery differs depending on the type--alkaline, lithium or zinc chloride. Batteries come in all shapes and sizes and are available in a wide range of strengths, in terms of...

A dry cell is a form of electric battery and is one of the most common types of batteries used today. A typical dry cell is a simple flashlight battery. Dry cells consist of a metal container or...

Lipids have many roles in the body, from serving a structural role in membranes and storing energy for later use to helping the brain transmit nervous impulses and regulating the function of the body.

Asexual reproduction involves only one organism as opposed to sexual reproduction which involves two organisms. Asexual reproduction takes place when a single cell divides to form daughter cells....

The cell surface membrane is a complex biochemical structure critical to the health and functioning of the cell. Eukaryotic cells---those characteristic of all organisms other than primitive ones...

In the anode, a chemical reaction causes the electrons and protons of the hydrogen atoms to split apart. The electrolyte has an especially designed film that allows the protons to pass through,...

A large block with two steel coil terminals, the 6-volt battery may look like a heavy-duty lead battery but is actually just four 1.5-volt carbon-zinc battery wired in a series and stored inside a...

In order to generate electricity through thermoelectric effects, a current must be generated by the combination of two semiconductor materials set at different temperatures. The thermoelectric...

Bacteria are adaptive, single-celled organisms that are everywhere on Earth. Bacteria are in the air, the oceans and even on human skin. Bacteria are grown in laboratories to study disease and...

Bacteria are some of the tiniest forms of life. Inhabiting every part of earth, including the hottest, most obscure areas, bacteria has survived longer than any complex life form on earth. Though...

DNA is the basis for life, and every cell has its own copy of an organism's genetic code. Molecular biology deals with the study of DNA and the encoding processes that turn genes into proteins....

Perhaps the most important way that mold spores differ from bacterial endospores is that molds are classified as so-called higher fungi. As such they feature what biologists term the eukaryotic...

Part of the answer to the question of where internal respiration takes place is that it takes place inside the lungs. By extension it also takes place inside the circulatory system of blood...

Sugar works in the body as a source of energy. Sugars can be found in many foods and can be classified into two categories: complex and simple. An example of a simple sugar is table sugar itself,...

Cell respiration is a complex process, with three different cycles. Glycolysis is responsible for breaking down glucose, and the electron transport chain takes electrons from the decomposition of...

Deoxyribonucleic acid, or DNA, can be found in cells and viruses. All living organisms rely on DNA for their genetic code, which pinpoints unique characteristics and some disorders. The process to...

It took a century for solar energy to catch on, but fueled by the steep rise in the cost of conventional electricity, advancements in solar cell technology are accelerating at and unprecedented pace.

A photocell is a relatively simple device that measures the presence of light. Photocells fall into two main categories: highly evolved versions that work with complicated equipment to help...

Pure silicon is the basic component of a solar cell. It is made from silicon dioxide, made of quartzite gravel or crushed quartz exposed to an electric arc to release oxygen. What is left is...

A cathode is an electrode in which electric current flows out of a polarized, electric device. A helpful way to remember the flow of current in a cathode is the mnemonic 'CCD': Cathode Current...

The cell is the most basic unit of life, but it engages in very complex behavior. The cell is constantly at work to maintain homeostasis. Homeostasis is essentially the cell trying to keep the...