What would be more damaging: having a head-on collision with an identical car at the same speed or driving head on into a crash barrier? explain

A head on collision would be worse and it would actually be four times as worse since the speed is doubled and energy is a squared value so by far a head on collision with another car

How is it possible that phylogenies based on sequences from nuclear genomes and organellar genomes (i.e., chloroplasts and mitochondria) from the same group of species yield phylogenetic trees with different branching orders?   answer :   the genome of the endosymbiont is more closely related to members of the group in which it originally evolved, while the nuclear genome of the engulfing organism has its own evolutionary trajectory.