Questions

The red blood corpuscles  or erythrocytes usually carry antigens and there are two types of antigens. The A group persons have antigen A in their red corpuscles and the B group have antigen B in their red corpuscles. The AB group person have both antigen A and antigen B in their erythrocytes. The 'O' group persons have no antigens in their red corpuscles.

Cretinism is a disease caused by hypothyroidism (less thyroxine formation) . The symptoms of the disease are retardation of mental, physical and sexual developments. potbelly, protruding tongue, dry skin etc are also indicative of this disease.

RST 4.5 is called as TRAP.

The first of the four stages of coal formation is lignite coal.

There are four stages of coal formation:

1. Peat,

2. Lignite,

3. Bituminous and

4. Anthracite.

The bacteria has removed a large portion of the other constituents of the plant matter and left around 25 to 34 percent.

Candidate Key – A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key. 

Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key.

• One needs to be very careful in selecting the Primary Key as an incorrect selection can adversely impact the database architect and future normalization. For a Candidate Key to qualify as a Primary Key, it should be Non-NULL and unique in any domain.