Comparison of the cell membrane to a city. in 2 sentence : )

The cell membrane can be compared to a city for many reasons. For one, look at the Nucleus. It runs everything. This can be compared to, perhaps a Mayor's office in a city? Or, the Endoplasmic Reticulum. This acts like a road, taking things to and fro, fro and to.

(Hope it helps) :)

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.