Why do mapping experiments become less accurate when the distances between genes become large? a. crossover gametes become less common. b. interference is greater when the distance between genes is large. c. multiple-strand exchanges are more common. d. recombination occurs less frequently in long chromosomes.

C-mutiple strands exchange are common.

Explanation:

The relative measure of distance between two linked genes is known as A MAP UNIT.it is also the distance between a gene and centromere,

The higher the fequemcies or the number of crossover (fexchanged of genetic mateials at meiosis i&iii,) the larger the MAP distances measured between genes.

Therefore the less accuracy is due to higher frequency of crossing over which increases the MAP distances making MAP units determination less accurate to measure ;since the distance from mutiple crossovers has double

The number of map unit is obtained by dividing the percentage of crossover by 2.

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the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.