Crossing over and independent assortment during meiosis increases what?

During meiosis, when homologous chromosomes are paired together, there are points along the chromosomes that make contact with the other pair. This point of contact is deemed the chiasmata and can allow the exchange of genetic information between chromosomes. This further increases genetic variation.

Explanation:

i hope this helped Mai-san :)

Sincerely~ Rantaro Amami

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.