Crypt
(Science: pathology) deep pit that protrudes down into the connective tissue surrounding the small intestine. The epithelium at the base of the crypt is the site of stem cell proliferation and the differentiated cells move upwards and are shed 3-5 days later at the tips of the villi.
If the balance of nature is left untouched, landscapes can change dramatically over time. A previous ecosystem is supers..
Organisms employ different strategies to boost its defenses against antigens. Humans have an immune system to combat pat..
In plants, growth occurs in meristems, which are the site of repeated cell division of unspecialized cells. These cells ..
Plants in lentic habitats have features not found in terrestrial plants. They acquired these features as they adapt to t..
This tutorial investigates perception as two people can interpret the same thing differently. Know more about human perc..
The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..