Initial dissolution of Tooth Substance by Acid

# In the carious process, the initial dissolution of the tooth substance by acid takes place in which of the following place?
A. Below the dentin Surface
B. Below the enamel surface
C. On the enamel surface
D. Towards the dentin

The correct answer is B. Below the Enamel Surface.

The top portion of the tooth remains intact and it's the subsurface which looses the minerals. This is the stage where it's called as incipient lesion. Once the top protion breaks, it's called a cavitated lesion.

Digestive System and Nutrition - MBBS BDS Entrance Examination

The correct answers are highlighted in green.

# Micelles are the bodies related to:
 A. Secretion of hormones
 B. Secretion of enzymes
 C. Absorption of minerals
 D. Absorption of fat

# Movements of circular muscles in the stomach is called
 A. Digestion
 B. Absorption
 C. Excretion
 D. Peristalsis

Sites of Various Metabolic Pathways

Sites	Metabolic Pathways
Mitochondria	Citric acid cycle Oxidative phosphorylation Fatty acid oxidation Electron transfer Synthesis of ketone bodies
Ribosomes	Protein Synthesis
Golgi Complex	Glycoprotein synthesis
Nucleolus	RNA Synthesis
Cytoplasm	Cholesterol synthesis Glycolysis Fatty acid synthesis Glycogenesis Glycogenolysis HMP shunt Gluconeogenesis
In both mitochondria and cytosol	Urea Cycle Gluconeogenesis

# Clotting factor common to extrinsic and intrinsic pathway is:

# Clotting factor common to extrinsic and intrinsic pathway is:
A. Factor II
B. Factor III
C. Factor V
D. Factor VII

The correct answer is C. Factor V.

Prothrombin activator that is formed in intrinsic and extrinsic pathways converts prothrombin

into thrombin in the presence of calcium (factor IV). 

Once formed thrombin initiates the formation of more thrombin molecules. The initially formed thrombin activates Factor V. Factor V in turn accelerates formation of both extrinsic and intrinsic prothrombin activator, which converts prothrombin into thrombin. This effect of thrombin is called positive feedback effect.