18. During meiosis, homologous chromosomes exchange genetic material. This exchange of genetic material -

A. increases the genetic variation

B. reduces the diploid number to the haploid number

C. increases the haploid
number to the diploid number

D. reduces the probability of mutations

During meiosis, homologous chromosomes exchange genetic material. This exchange of genetic material - A. increases the genetic variation.

During meiosis, homologous chromosomes may exchange genetic material during a process called "crossing over."

So, the correct answer is Crossing over produces new combinations of genes on alleles, increasing genetic variation.

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A. increases the genetic variation

that's why individuals don't look like their partents. This process is called crossing-over