How is the 'sixth episode of extinction' of species of earth, now currently in progress, different from the five earlier episodes ? What is it due to ? Explain the various causes that have brought about this difference.

How is the presently occuring species extinction different from the earlier mass extinctions ?

Since the origin of life on Earth, there were five episodes of mass extinction of species . (i) How is the 'Sixth Extinction', presently in progress, different from the previous episodes ? (ii) Who is mainly responsible for the 'Sixth Extinction' ? (iii) List any four points that can help to overcome this disaster.

What is codominance ? Explain it with suitable example. How does it differ from incomplete dominance?

(a) Define electric current. What is the SI unit of electric current. (b) One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor? (c) Which instrument is used to measure electric current? How should it be connected in a circuit? (d) What is the conventional direction of the flow of electric current? How does it differ from the direction of flow of electrons? (e) A flash of lightning carries 10C of charge which flows for 0.01s. what is the current? If the voltage is 10MV, what is the energy?