Yes that is true. The gray matter of the cerebrum is the area of the brain where nerve cell bodies make connections, called synapses, that control brain activity.
White matter, on the other hand, is mostly the axons of neurons. The pale fatty insulator of axons, myelin, is mainly responsible for their whitish appearance on gross examination.
Xerostomia
The medical term for this condition is xerostomia. Xerostomia
refers to abnormal dryness of the mouth which may be caused by a reduction in
the volume of saliva. Saliva is an important fluid in the body that assists to
protect and maintain oral health.
One reason could be that they do not have most of the seven characteristics of life (reproduction, homeostasis, heredity, response to the environment, growth, cellular organization, and metabolism.)
You can use TT or Tt for Tall plants
You can use tt Short plants
Capital T can stand for tall while lower case t stands for short
