Who was the first to perform the surgery of human heart transplant ?

The genetic material of a cell is in :

Citrus fruits are notable for being good source of a specific vitamin. Which is that vitamin?

The French army doctor Charles Louis Alphonse Laveran was awarded the Nobel Prize for Physiology or Medicine in 1907. What was his major discovery? 

Ordinary white light (sunlight) is made up of different colours. Among these which one has greater wavelength?

Which is the most abundant metal found in the earth's crust?