types of birth defects

Types of defects in Crystals - The defect, which arises due to the irregularity in the arrangement of atoms or ions are called point defects. Point defects are of three types: Stoichiometric defects Non-stoichiometric defect..

The defect, which arises due to the irregularity in the arrangement of atoms or ions are called point defects..

This type of defect is present in those compounds which have Low co-ordination number. Large difference in size of anion and cation. Examples: AgCl, AgBr, AgI and Z..

If imperfections in the crystal are such that the ratio between the anions and cations remain same as represented by the molecular formula, the defect is called a stoichiometric defect. There are three types of stoichiometric defects: Schottky defect Fre..

In in ionic crystal of the type A + B - , equal number of anions and cations are missing from the lattice sites so that electrical neutrality is maintained it is called schottky defect. fig 2.29 - Schottky defect..

According to third law of thermodynamic it is only at OK that true crystals passes perfect order of arrangement of atoms in pure crystals. But with rise in temperature some derivations from complete order takes place. Presence of impurities also adds to disorder. "Any departure from perfectly order..

If an imperfection causes the ratio of cations to anions to become different from that indicated by the ideal chemical formula, the defect is called non-stoichiometric. There are three types: Metal excess Metal deficiency Impurity defects..

Group 13 elements such as Ga and Al and group 15 elements such as P and As can enter the crystal structure of group 14 elements Ge or Si substitutionally. Group 15 elements have one excess valence electron as compared to Group 14 elements (Si or Ge). Therefore after forming four covalent bonds, on..

Innate or Inborn Immunity - The type of immunity inherited by the organism from the parents and protects it from birth throughout life is known as innate or inborn immunity. Example: Human beings have innate immunity against distemper a fatal disease of dog..

[a]pyrene is a known precursor to cancer causing metabolites in laboratory animals. Various studies have determined that this compound is toxic. It is converted by cytochrome P450 to a variety of oxides that react with DNA, making them highly mutagenic. The newborn animals of pregnant mice fed benz..