Genetic recombination refers to the process by which two DNA  molecules exchange genetic information. The three types of genetic  recombination are crossing over, conservati â¦ ve site-specific  recombination and transpositional recombination.
This produces a crystal lattice, which is commonly known as 'ice'. Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a liter of ice weighs less than a liter water. The heavier water displaces the lighter ice, so ice floats to the top. One consequence of this is that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over.
The âtip of the icebergâ expression can be explained as follows: Icebergs float because the density of ice (around 900 kg per cubic meter) is lower than that of seawater (around 1025 kg per cubic meter). The ratio of these densities tells us that 7/8 of the icebergâs mass must be below water.