Regina's Biology Blog September 2006 Archive

Astrocyte Glial Cell © Dennis Kunkel Glia are cells of the nervous system. They compose a voluminous support system that is essential to the proper operation of nervous ... Read More

All animals have common names. These names may be different for the male, female, and young of a species. They may also be different for different groups of animals. For example, ... Read More

Zina Deretsky, NSF Researchers are using tree rings to measure hurricane activity from over 200 years ago. Scientists have discovered that trees located in areas that have been ... Read More

Lily Anther Microsporocytes © John C. Glase Meiosis is the process of cell division that occurs in sex cells. It produces gametes with one half the number ... Read More

Chromatin is the mass of genetic material, composed of DNA and proteins, that condenses to form chromosomes in eukaryotic cell division. Chromatin is located in the cell's nucleus. Additional Reading: Cell ... Read More

Neuronal cytoskeleton, Image courtesy of Mark Goldberg The cytoskeleton is a network of fibers located throughout the cell's cytoplasm. These fibers give support to the cell and ... Read More

Credit: University of Michigan Researchers have discovered the mechanisms by which older stem cells shut themselves down. The study, published in the journal Nature, suggests that this shut ... Read More

Ribosomes are the protein assemblers of a eukaryotic cell. They are typically composed of two subunits: a large subunit and a small subunit. These two units join together to ... Read More

Muscle tissue is made of excitable cells that are capable of contraction. This tissue is the most abundant tissue in most animals. There are three major types of muscle ... Read More

If a baby kangaroo is called a joey and a baby eagle is called an eaglet, what is a baby llama called? Try this fun and informative trivia game on the ... Read More

Nervous tissue is responsible for sensing stimuli and transmitting signals. A neuron, or nerve cell, consists of two major parts: a cell body and nerve processes. The central cell body contains ... Read More

Virus injecting its genetic material into a bacterium.© Gary E. Kaiser A single virus particle (virion) is in and of itself essentially inert. Viruses cannot reproduce or express their ... Read More

The human body is organized on various levels. Each of these levels builds on the other to comprise an organism. For example, cells make up tissues, tissues make up organs, ... Read More

The brain is the control center of the body. Think of a telephone operator who answers incoming calls and directs them to where they need to go. Similarly, your brain ... Read More