Basically, the cell wouldn't be able to "breathe," as the mitochondria is where the respiratory functions of the cell happens. No energy would be produced, and then the cell would stop moving and die.
Id say one of the negative affects is how cold it is in a tundra biome so its harder to get food and overall harder to survive
This is referring to meiosis, which happens just once to make reproductive cells, unlike mitosis which is just simple copying.
In mitosis, one cell splits into two, but the number of chromosomes doesn't change. The original cell makes two copies of its chromosomes and divides them up.

In <em>meiosis</em>, however, our cell doesn't bother making those two copies. It just takes what it has and divides it between two new cells.