Tiers

In Fischer‚aas neo-Piagetian skill theory, the broadest set of distinctions in the degree of hierarchical integration of an action and thought. Accordingly, there are four tiers of development Reflexes, sensorimotor actions, representations and abstractions. The concept of tier and the related concept of levels stands parallel but in contrast to the Piagetian notion of stage. …

Thrombophilic disorders

A disorder of the hemopoietic system responsible for the formation of blood cells in which there is a tendency to the occurrence of thrombosis (blood clots). When these occur in the brain, they can cause hemiplegia . See Cerebral palsies, Spastic hemiplegia

Thymine

Also known as 5-methyl-2, 6-dioxytetrahydropyridime, it is one of four molecules that form the base pairs of DNA, but not RNA. In DNA, it is always paired with the purine adenine.  See Adenine, DNA (deoxyribonucleic acid), Nucleotide, Pyrimidines, Purines, RNA

Theory of the germ plasm

The theory of Augustus Weismann (1834-1914) that the cells destined to become reproductive cells are segregated very early in development and are thus untouched by influences from the environment or from anywhere else in the body. They are transmitted unchanged from generation to generation (and thus are ‘immortal’) and have no role in development, but …

Theory of the child’s mind (ToM)

A set of interrelated principles and propositions that explains something of why children think and feel as they do, how they come to understand other people’s minds or mental (beliefs, desires, emotions, imagination, intentions) states, and why and how changes come about.  The theory seemingly started with the question “Do the chimpanzee have a theory …