Questions

In the following question, a sentence has been given in Direct/Indirect speech. Out of the four alternatives suggested, select the one which best expresses the same sentence in Direct/Indirect speech.

"Please don't cry" he said.

Polyploidy is involved in which of the following examples?

What are the building blocks of Nucleic Acids?

Isotopes are atoms of the same element that have different

What is the general formula for a straight-chain alkane?

What is the difference between the following declarations?

extern int fun();

int fun();

A sentence/a part of the sentence is underlined. Four alternatives are given to the underlined part which will improve the sentence. Choose the correct alternative and click the button corresponding to it. In case no improvement is needed, click the button corresponding to “No improvement”.

The greater the demand, higher the price.

Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.

The antigen-antibody immunological reaction is used to be regarded as typical of immunological responses. Antibodies are proteins synthesized by specialized cells called plasma cells, which are formed by lymphocytes (cells from the lymph system) when an antigen, a substance foreign to an organism's body, comes in contact with lymphocytes. Two important manifestations of antigen-antibody immunity are lysis, the rapid physical rupture of antigenic cells and the liberation of their contents into the surrounding medium, and phagocytosis, a process in which antigenic particles are engulfed by and very often digested by macrophages and polymorphs. The process of lysis is executed by a complex and unstable blood constituent known as complement, which will not work unless it is activated by a specific antibody; the process of phagocytosis is greatly facilitated when the particles to be engulfed are coated by a specific antibody directed against them.

What happens when an antigen comes in contact with lymphocytes?