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Homologous chromosomes during prophase I - Animation

By: HWC, Views: 6893

The chromosomes were duplicated during interphase and the sister chromatids are now in thin threadlike form. Each chromosome becomes zippered to its homologue, so that all four chromatids are closely aligned. The chromosomes are tightly aligned, but we will show them as separate so that y...

Neuron Structure Animation

By: Administrator, Views: 12358

There are several types of neurons, three of which are: Motor neurons, Sensory neurons, Interneurons. The nervous system is usually described as having two interconnected divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). CNS: Includes the brain and spinal...

Spinal Cord Injury Animation

By: Administrator, Views: 12234

The most common cause of spinal cord injury is trauma. Spinal cord injury is most common in young, white men. Spinal cord injury can be either complete or incomplete. In complete injuries there is no function below the level of injury. In incomplete injuries there is some function remaining...

Natural Selection, Species Isolation and Real World Example

By: HWC, Views: 8421

`Natural selection' is the process in which organisms with adaptive traits survive and breed in greater number than organisms without such traits. Eventually, almost all of the individuals in the population will have the same adaptive trait. This was the concept presented by Charles Darwin in ...

DNA fingerprinting Animation

By: HWC, Views: 5855

DNA fingerprinting enables a scientist to compare the DNA from two biological samples, such as a blood stain and a suspect's blood. A restriction enzyme is added to the samples to be compared. The enzyme cuts the DNA into smaller fragments. The DNA fragments are placed on an electrophor...

Cataract

By: Administrator, Views: 11887

A cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may re...

Component of feedback systems & Communication and regulation of body systems

By: HWC, Views: 9096

• Primary responsibility for communication and regulation in the body is shared by the nervous and endocrine systems. • The two systems work alone or together in specialized physiological processes called feedback systems to maintain homeostasis. • Feedback systems - or loops - are ...

Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 8835

• Dissociation of the chemical substances in the body fluids can result in the production of free hydrogen ions. • The pH scale is used to measure the concentration of hydrogen ions in solution. • Normal blood pH values vary around 7.4. • When hydrogen ion concentration increases, t...

Introduction to Autism

By: Administrator, Views: 12328

Autism is a developmental disorder characterized by difficulties with social interaction and communication, and by restricted and repetitive behavior. Parents usually notice signs during the first three years of their child's life. These signs often develop gradually, though some children with au...