These genetic variants are believed to cause changes in the way the bodyâs T cells behave. T cells are immune system cells that normally fight off harmful invaders, such as viruses and bacteria. In people with psoriasis, however, T cells also attack healthy skin cells by mistake. This immune system response results in a range of reactions, including: 1  enlargement of blood vessels in the skin.  increase in white blood cells that stimulate the skin to produce new cells more quickly than usual.
Teeth. Zebra have several types of teeth that help them survive in their habitats. In the front of their mouths, zebra use their strong incisors for biting off grass and other vegetation. In the rear of their mouths, zebra have molars and premolars to grind down their food.
The plains zebra and the mountain zebra resemble horses, while the Grevy's zebra is related to the ass.Grevy's zebras live in semi-desert areas. Tough grasses form the bulk of this endangered zebra's diet. They also eat plenty of leaves, which can sometimes form up to 30 percent of their diet. There are two types of mountain zebra: Cape mountain zebras, which were almost hunted into extinction in the early 20th century, and the Hartmann's mountain zebra. They both eat a few types of grass, ignoring others. Themeda triandra, Cymbopogon plurinodis and Setaria neglecta are a few varieties they prefer.