porphyria
A pathological state in man and some lower animals that is often due to genetic factors, is characterised by abnormalities of porphyrin metabolism and results in the excretion of large quantities of porphyrins in the urine and in extreme sensitivity to light.
A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..
Regulation of Biological Systems tutorials are focused on the modulation of biological systems from cell to population l..
Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..
Illusions are the perceptions and sensory data obtained from situations in which human error prevents us from seeing the..
Ferns and their relatives are vascular plants, meaning they have xylem and phloem tissues. Because of the presence of va..
Learn how the way genes control and determine every aspect of the body. This lesson uses lac operon as an example. ..
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