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Hormones and the menstrual cycle Animation

By: HWC, Views: 4710

Feedback loops to the hypothalamus and pituitary gland from the ovaries during the menstrual cycle Animation for a step-by-step explanation. Production of a releasing hormone (GnRH) by the hypothalamus prods the pituitary's anterior lobe to release FSH and LH. In the ovary, FSH and LH stimula...

Homologous chromosomes during prophase I - Animation

By: HWC, Views: 5657

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: 11121

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: 11058

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...

DNA fingerprinting Animation

By: HWC, Views: 4731

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...

Interpreting a cladogram Animation

By: HWC, Views: 1426

Using a cladogram to determine relative relatedness and whether the lungfish is more closely related to a human or to a trout. To determine the relative relatedness, we begin by tracing the branches from the human and the lungfish to the point where they meet. We'll call this node 1. Now...

Condensation and Hydrolysis Animation

By: HWC, Views: 1611

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

Complement Proteins Animation

By: HWC, Views: 4537

Formation of membrane attack complexes. Complement proteins can activate when they bind to antibodies that are bound to a pathogen. Complement proteins also activate when they bind directly to bacterial surfaces. Cascading reactions yield huge numbers of different types of complement protei...

The 4 steps of translation Animation

By: HWC, Views: 3603

Translation is the process of formation of a polypeptide chain according to codon present in mRNA. The four steps of translation are: Activation or charging of tRNA Initiation – recognition of start codon, binding of ribosomal subunits to mRNA and formation of initiation complex with Met-tR...