Answer: Genetically engineered crops have an advantageous gene from another organism inserted into their genome.
Ken and Kendra share 50% of their genes. Lara an Lonnie share 100% of their genes.
The fraternal twins are just siblings that share the same womb. Each of them starts it's development as separate egg that is fertilized by a separate sperm, so they are no more similar than the other siblings.
The biological (identical) twins, on the other hand, come from the same fertilized egg, thus they share the same genes.
The answer is low light intensity! I hope this helps!