There are two types of polar climate: ET, or tundra climate; and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above 0 °C (32 °F), while an ice cap climate has no months above 0 °C (32 °F).
I have to say airborne infections. If the infection is airborne it can travel and infect many people more quickly and wide spread.
The size and position of their centres are the same for homologous Chromosomes
