Questions

Ichthyology is the branch of biology devoted to the study of fish.

It is also known as Fish science which includes bony fishes (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha).

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.

The words do, does and did often cause confusion in the English language. They are all forms of the verb to do.

It is also common to use do, does and did as auxiliary verbs (or helping verbs) together with another verb in its base form. This is used to create negative sentences, questions, or for adding emphasis.

Examples :: 

* Russel did a great job on his debut match for team.

* Did you catch the train this morning?

* When did they arrive home?

Main memory works in conjunction with CPU.

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.