Winterbottom’s sign
(Science: clinical sign) swelling of the posterior cervical lymph nodes, characteristic of early stages of african trypanosomiasis; useful for surveys or control of migrations from endemic areas of persons with preclinical infections.
This tutorial investigates the genetic diversity in more detail. It also delineates how certain alleles are favored over..
Multicellular organisms evolved. The first ones were likely in the form of sponges. Multicellularity led to the evolutio..
Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..
There are many environmental factors that arise due to the usage of water in one way or another and for every action tha..
Plant organs are comprised of tissues working together for a common function. The different types of plant tissues are m..
Lentic or still water communities can vary greatly in appearance -- from a small temporary puddle to a large lake. The s..