What is genetic variation? A. Each individual in a population has slightly different genes.
B. Some individuals in a population have more genes than others.
C. Each population of a species has slightly different genes.
D. Some populations of a species have more genes than others.

Answer choice A.

genetic variation is the result of random mating creates unique offspring.

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

C.over 1 million refugees were displaced.