21. Which of the following events are NOT caused by differences in gene expression? (pick 2)
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Albino organisms are completely unable to produce melanin.
Cancer cells skip important cell cycle checkpoints, causing unregulated cell division.
During embryonic development, identical cells differentiate into skin cells, muscle cells, nerve cells, etc.
An Arctic hare's fur changes from white to brown during the summer months.
The correct options would be:
1. During embryonic development, identical cells differentiate into skin cells, muscle cells, nerve cells, etc.
2. An Arctic hare's fur changes from white to brown during the summer months.
These events are not caused by differences in gene expression but rather by other mechanisms such as programmed cell differentiation and seasonal adaptations.