Questions

An autoimmune disease is a condition in which your immune system mistakenly attacks your body.

The immune system normally guards against germs like bacteria and viruses. When it senses these foreign invaders, it sends out an army of fighter cells to attack them. Normally, the immune system can tell the difference between foreign cells and your own cells.

In an autoimmune disease, the immune system mistakes part of your body — like your joints or skin — as foreign. It releases proteins called autoantibodies that attack healthy cells. Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like lupus, affect the whole body.

Hence, Systematic lupus erythematosus is an autoimmune disease that affects multiple organs.

Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun.

• Kepler’s three laws of planetary motion can be stated as follows:

(1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci.

(2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.

(3) The squares of the sidereal periods (of revolution) of the planets are directly proportional to the cubes of their mean distances from the Sun.

In business, a takeover is the purchase of one company by another.

It is an investment strategy that involves the buying of money market instruments or currencies in anticipation of a price rise or a future increase in demand. Buying forward allows an investor to take advantage of future and potential profits by buying now at alower price, and selling when prices rise.

SI Bhyrappa

A search engine is a information retrieval program that constantly collects information on the Web, following links in Web sites and reading Web pages. The search results are presented in a list format and are called as hits.

A metasearch engine is a search tool that uses another search engine's data to produce its own results from the Internet. These engines take input from a user and simultaneously send out queries to third party search engines for results. It searches other search engines rather than individual Web sites.

Examples of Metasearch engine includes - Dogpile, Zoo, Yabado, Metager, etc...