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Interspecific Competition Relationship - Competitive & Niche Differentiation

By: HWC, Views: 7408

In an environment with limited resources, any organisms that utilize the same resources will be in competition with each other. For example, let's look at two competing species of paramecium, a single-celled organism that feeds on bacteria. If we raise each of these species in isolation, both...

Cell mediated immune response to a viral infection Animation

By: HWC, Views: 3751

Intracellular pathogens are the targets of cell-mediated immune response. The process begins when a virus infects a macrophage. Another macrophage engulfs the same virus or an antigen from it. In both cells, enzymes cleave the viral antigens into small bits. The fragments move to the cell sur...

Miller's reaction chamber experiment Animation

By: HWC, Views: 1303

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...

Replication of DNA and Chromosomes/ How do cells replicate their DNA? (Animation) no Audio

By: HWC, Views: 7463

DNA replication in E. coil begins at a site called oriC where a replication bubble forms. At either end of this bubble is a replication fork. Since DNA polymerase Ill can read its DNA template strand only in the 3' to 5' direction this means that one strand (leading) can be read continuously b...

Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 7204

Here are the molecular formulas of three different amino acids. All amino acids share this backbone. The main difference between every amino acid is the side groups seen here, and these side groups give each of the amino acids their different characteristics. But before we get into that, let's ...

Brain Lobes Animation

By: Administrator, Views: 11848

The brain’s cerebral cortex is the outermost layer that gives the brain its characteristic wrinkly appearance. The cerebral cortex is divided lengthways into two cerebral hemispheres connected by the corpus callosum. Traditionally, each of the hemispheres has been divided into four lobes: front...

Brain Anatomy Animation (Part 2 of 2)

By: Administrator, Views: 11953

Its nervous tissue consists of millions of nerve cells and fibers. It is the largest mass of nervous tissue in the body. The brain is enclosed by three membranes known collectively as the meninges: dura mater arachnoid pia mater The major structures are the: cerebrum cerebellum dienc...